EW4 Smart Watch User Manual

Thank you for purchasing our products. This manual addresses the safety guidelines, warranty, and operating instructions. Please review this manual thoroughly before operating your device. All pictures in this manual are for illustration purpose only. Actual product may vary due to product firmware upgrade and app upgrade.

Getting Started

What's in the Box

The box contains:

• A Smart watch (EW4 with bands)
• A Charging cable
• A Quick start guide

What's in this Document

This manual gets you started quickly with setting up your watch. Setup ensures that your watch can synchronize its data with the Letsfit app, where you can get detailed information on your stats, view historical trends, log sleep, and more. As soon as setup is complete, you're ready to start moving. The remainder of the manual walks you through every function on your EW4.

Setting up Your Watch

Charging Your Watch

Please fully charge your watch before initial use.

1. Insert the USB plug of the charging cable into the USB port on your computer or a UL-certified USB wall charger.
2. Hold the other end of the charging cable near the port on the back of the watch until it attaches magnetically.
3. Make sure the pins on the charging cable lock securely with the port. The connection is secure when the watch vibrates and the battery icon with percent charged appears on the screen.

When the watch shows that the battery is low, connect the watch to a USB port with 5V-500mA. While the watch charges, there is a battery progress bar on the screen and you can check the battery level at any time.

4. Remove the watch from the power supply once fully charged.

• USB charger requirement: DC USB port (5V-500mA)
• Charging time: Approximately 2 hours

Disassembling / Assembling Your Watch

Disassembly

1. To remove the wristbands, turn over the watch and find the quick-release lever.
2. While pressing the quick-release lever inward, gently pull the wristband away from the watch to release it.
3. Repeat on the other side.

Assembly

1. To reattach the wristbands, slide the pin (the side opposite the quick-release lever) into the notch on the watch. Attach the wristband with the clasp to the top of the watch.
2. While pressing the quick-release lever inward, slide the other end of the wristband into place.
3. When both ends of the pin are inserted, release the quick-release lever.

Wearing Your Watch

All-day Wear and Exercise

For all-day wear when you're not exercising, wear the device on your wrist horizontally, a finger's width below your wrist bone and lying flat, the same way you would put on a watch.

For optimized heart rate tracking, keep these tips in mind:

1. Experiment with wearing the watch higher on your wrist during exercise. Because the blood flow in your arm increases the farther up you go, moving the watch up a couple of inches can improve the heart rate signal. Also, many exercises such as bike riding or weight lifting require you to bend your wrist frequently, which is more likely to interfere with the heart rate signal if the watch is lower on your wrist.
2. Do not wear your watch too tight. A tight band restricts blood flow, potentially affecting the heart rate signal. This being said, the watch should also be slightly tighter (snug but not constricting) during exercise than during all-day wear.

Using Your Watch

App Installation

Use the watch with our customized Letsfit app. You can download Letsfit from App Store / Google Play or scan the QR codes below to download.

iOS

[QR Code for iOS App Download]

Android

[QR Code for Android App Download]

Note: Letsfit app is only compatible with smartphones, not tablets or PCs.

Smart Phone System Requirements

• iOS 11.0 & higher
• Android 6.0 & higher
• Bluetooth 4.0 & higher

Account Registration and Login

Please register an account with a valid email address. After registration, check your email box to complete email verification, and then tap "Verified" to log in.

Pairing the Watch with Your Phone

Please pair the watch with your phone in the Letsfit app, NOT in the Bluetooth settings of your phone.

Correct: Pair the watch with your smartphone in the Letsfit app

Incorrect: Do NOT pair the watch with your smartphone in your phone's Bluetooth settings [Bluetooth icon ?]

1. Enable the Bluetooth ? of your smartphone.
2. Open the Letsfit app on your smartphone and go to the "Device" page, tap "+ Pair new device".
3. Tap [Scan icon] , and your smartphone starts scanning.
4. Use the Letsfit app to scan the QR code on the watch screen.
5. Tap "✔️" on the watch to connect the watch to your smartphone.

Notes:

• You can also search this device in the app to pair (Go to the "Device" page → "+ Pair new device" → tap "EW4" under "Search Devices").
• Once the watch is connected to your app, the watch will automatically search and reconnect itself if the connection is lost or when Bluetooth is restarted after manual disconnection.
• If you unpair the watch with the app, the information on the watch will be reset and the watch will be restarted. Please do not unpair the watch with the app unless there is an issue that will require a reset.
• The watch can only pair with one smartphone at a time. When pairing, please ensure the watch and your smartphone is within 0.5 meters distance.

App Interfaces

Swipe down [down arrow symbol] to sync data.

Summary Screen

Displays activity data including Daily Workout Minutes, Daily Active Hours, and Daily Steps.

Training Screen

When you start a sport mode on your watch, detailed data and graphs will be displayed here after the exercise is over (swipe down to sync data first).

Device Screen

Tap "EW4" [Device icon ⚙️], you can customize call / message / alarm alert or set other parameters.

Getting to Know Your Watch

Button Controls

Up button

• Press to wake the screen, go to the function list, return to the home screen, or pause/resume the sport.
• Hold to end the sport mode or power on/off the watch.

Down button

• Press to go to the Training interface, enter the sport tracking mode, or flip through exercise data during sports.

Watch Interfaces

This is a touch screen; swipe the screen to go to different interfaces, tap to enter the function, and swipe the screen to the right [right arrow symbol] to return to the previous interface.

The home screen is the clock. On the clock:

• Swipe down [down arrow symbol] to see notifications.
• Swipe up [up arrow symbol] to go to the status bar (brightness control, do not disturb ?, settings ⚙️, wrist sense).
• Swipe left/right [left/right arrow symbols] to switch among function shortcuts (daily activity data ?, heart rate ❤️, stress monitoring ?, sleep ?).

Notifications

When messages (like Facebook, Twitter) come in, the watch vibrates to alert you, and the screen displays the message content.

Home Screen Customization

You can customize the home screen by following the steps below:

Method 1 (on the watch):

1. Tap and hold the home screen.
2. Swipe left/right to choose one and tap to confirm.

Method 2 (in the app):

1. Open the Letsfit app, go to the "Settings" page → "EW4" → tap "Watch Faces".
2. Select a watch face or choose a photo in your phone album to display on the home screen.
3. Tap "Confirm" to finish setting.

Function List

• ? Tracking Sports: Tracks your exercise data in up to 14 sports modes. Choose the mode that you want to start on the watch.
• ? Breath Training: Guides your breathing for a relaxation.
• ? Daily Training Data: Records your daily training data.
• ⏱️ Stopwatch: Use the stopwatch to make your exercise more standardized.
• ❤️ Heart Rate: Tracks your real-time heart rate automatically and continuously.
• ⏳ Timer: Customize your timer.
• ? Sleep: Check your daily sleep data.
• O₂ Blood Oxygen Level: Measure your blood oxygen level.
• ? Stress Level: Monitors your daily stress and generates a stress score based on your heart rate variability.
• ⏰ Alarms: Set alarms to have the watch vibrates to wake you up, take pills, and more.
• ? Controlling Phone Music: Control the music playing of your smartphone.
• ⚙️ Basic Settings: Some basic settings and information of the watch.

Detailed Functions

1. Tracking Sports

The watch tracks your exercise data in up to 14 sports modes.

Start a sport

Press the down button to go to the Training interface → Swipe the screen to select a sports mode you want to start.

Set a target

Before beginning an exercise, you can set training goals such as distance, duration, calories burned, etc. Tap [Target icon] beside the sport mode and set your target.

Add a virtual running competitor

In the Outdoor run mode, you can set a virtual running competitor and the competitor's running pace, and check the gap between yourself and the competitor in real time to improve your running performance more effectively.

1. Tap "Training" in the function list.
2. Tap [Outdoor Run icon] beside "Outdoor run".
3. Tap "Smart competitor" and enable the function.
4. Tap "Target pace" → "Customise" to set the competitor's pace.
5. Tap "✔️" to confirm.
6. Return to the training interface and tap "Outdoor Run" to start your running with the competitor. You can view the running pace of the competitor and you on the watch during the exercise.

Use your phone's GPS to track sports

(Only for Outdoor Run / Outdoor Walk / Outdoor Cycle / Hiking modes)

You can use the GPS of your phone to track your pace & distance during these sports while mapping out your exercise on your phone (take your phone with you to use the GPS function during exercise).

When you start an outdoor sport, the watch begins searching GPS signal. Please let the Letsfit app run in the background and allow the location services ? on your phone, then move to an open area and stand still to better receive the signal. After the GPS is connected, the watch will start tracking the sport. [GPS Connected icon]

For best results, wait for the signal to be discovered before you start your activity.

If you don't want to wait for the GPS signal to be discovered, tap "Skip" to move to the activity screen and get started. But your movement route cannot be displayed before successful positioning. Sport starts after successful positioning or skipping positioning.

Note: GPS is required for calculating your distance in Outdoor Cycle. Please wait for successful GPS positioning before start.

During sports

• Swipe the screen up/down to flip through exercise data.
• Press the up button to pause/resume the sport.

End the sport

Hold the up button until the circle is full to end the sport. Exercise data is displayed after the exercise has ended. Swipe up the screen to flip through exercise data.

Notes:

• After ending an exercise, you can view detailed data and graphs in the app (Go to the "Training" page, swipe down the page to synchronize data, and tap the exercise you just ended).
• After you finish the exercise in GPS mode, your movement route will be displayed in the app (Go to the "Training" page of the app, and then tap on the exercise you just ended to view).
• Data of exercises less than one minute will not be saved.
• When the battery ? level is less than 10%, the watch enters low battery mode, at which you cannot start a sports mode. Please charge the watch to operate it again.

2. Tracking Daily Activity Data

The watch tracks your all-day activity data, including steps, calories burned and distance.

3. Monitoring Heart Rate

Tap "Heart Rate" ❤️ in the function list to enter the heart rate interface, the watch will automatically measure your real-time heart rate. You can also view your all-day heart rate data in the heart rate interface of the watch or in the app.

Note: To monitor heart rate more accurately, wear the watch on the upper position of your wrist and a bit tighter than usual when you exercise. In addition, complete your profile in the app.

4. Tracking Sleep

The watch automatically tracks your sleep duration and consistency with a comprehensive analysis of sleep quality data. Tap "Sleep" ? in the function list so you can check your sleep records and improve your routine.

5. Measuring Blood Oxygen Level

Before measuring, wear the watch a finger-width below the wrist bone and a bit tighter than usual.

1. Tap "Blood Oxygen" O₂ to enter the blood oxygen level detection mode.
2. When measuring, keep your arm flush with your chest and the watch screen facing up. Keep your arm still to ensure the accuracy of the data.

Note: The measurement data may be incorrect due to movement or finger tapping. Please keep still and tap [Measure icon] to measure again.

6. Monitoring Stress Level

Based on your heart rate variability, your stress score helps you see if your body is showing signs of stress on a daily basis. The score ranges from 1 to 100, where a higher number means your body is showing more signs of physical stress. To see your daily stress score, wear your watch to sleep.

1. Tap "Stress" ? in the function list to enter the stress measuring mode.
2. When measuring, keep your arm flush with your chest and the watch screen facing up. Keep your arm still to ensure the accuracy of the data.

7. Breath Training

Tap "Breath training" ? in the function list to enter breathing mode. Select the rhythm and duration of the breathing training. Then tap [Start icon] to start and follow the instructions to breathe. If you want to end the breathing training, press the up button to exit.

8. Setting Alarms

Method 1 (On the watch):

1. Tap "Alarm" ⏰ in the function list.
2. Tap "+" to add an alarm. Set the alarm time, and repeat days.
3. Tap [Add alarm icon] to add the alarm.

Notes:

• You can set up to ten alarms on the watch.
• To enable/disable the alarm, tap "Alarm" on the watch and then choose to turn on/off the alarm you set.

Method 2 (In the app):

1. Go to the "Settings" page in the Letsfit app and tap "EW4".
2. Tap "Sleep Alarm" to enter the alarm setting interface.
3. Tap "Add" to add an alarm.
4. Set the alarm time, title, vibration period and repeat days.
5. Tap "Confirm" to save your settings.

9. Controlling Phone Music

After the watch is connected to your phone ?, tap "Music" ? in the function list and control the music playing on your phone.

Note: You can only control the music player that's running on your phone.

10. More Functions

10.1 Call Notification

When there is an incoming call ?, the watch vibrates to alert you, and the screen displays the caller ID. Tap [Reject call icon] on the watch screen to reject the call.

Notes:

• Only when "Notification alerts" is enabled in the app ("Settings" page → "EW4" → "Notification alerts", turn on "Notification alerts"), will calls be notified.
• When the "Do not disturb" ? function is enabled in the app ("Settings" page → "EW4" → "Do Not Disturb") or on the watch (Status bar → [DND icon]), calls will not be notified on the watch during the do-not-disturb period.

10.2 Message Notification

When messages (like Facebook, Twitter, and Instagram messages) come in, the watch vibrates to alert you, and the screen displays the message content.

Notes:

• Only when "Notification alerts" is enabled in the app ("Settings" page → "EW4" → "Notification alerts", turn on "Notification alerts"), will messages be notified.
• When the "Do not disturb" ? function is enabled in the app ("Settings" page → "EW4" → "Do Not Disturb") or on the watch (Status bar), messages will not be notified on the watch during the do-not-disturb period.

10.3 Sedentary Reminder

The watch vibrates to remind you to get up and move around ? when you have been sitting too long ("Activity" page → "Active Hours" → "Sedentary Alert Settings", enable the movement reminders function and set the remind interval.)

Basic Specifications

• Model No.: EW4
• Sync: Bluetooth 5.0 ?
• Screen: 1.28" color LCD
• Battery Capacity: 300mAh ?
• Working Voltage: 5V-500 mA
• Working Temperature: -10°C to 40°C
• Weight: 1.48oz (42g)
• Waterproof Rating: 5ATM
• Working Time: about 10 days

FAQs

Failure to pair the watch with the Letsfit app on your smartphone again

1. Tap "Settings" ⚙️ → "Reset" on the watch, and tap "✔️" to confirm.
2. Use the Letsfit app to scan the QR code ? displayed on your watch to pair.

If you still fail to connect the watch to the app, please kindly take the following steps:

1. Make sure your smartphone's Bluetooth ? is enabled and make sure the watch is not connected to other smartphones.
2. Make sure the distance between your smartphone and the watch does not exceed 0.5 meters and keep the watch screen always on when pairing.

Occasional failure to connect with Bluetooth

Reboot your smartphone or restart your smartphone's Bluetooth ?.

Failure to receive message / calls notifications

Message / calls notification function works when the watch connects to your smartphone via the app. Please kindly refer to the following tips:

1. Go to your smartphone Settings ⚙️, find Letsfit app, and enable the Location ? and all Notifications.
2. Enable your phone's Bluetooth ? and go to the Letsfit app to pair the watch.
3. Open the app. Go to the "Settings" page → "EW4" → "Notification alerts", turn on "Notification alerts".
4. Make sure the "Do not disturb" ? function is not enabled in the app or the watch.

The watch is disconnected from the Letsfit app on your smartphone

The watch will disconnect from your smartphone in the following cases:

1. Smartphone Bluetooth ? is off or exceeds the Bluetooth connection range (the maximum Bluetooth connection range is 10 meters and can easily be reduced by walls, furniture, etc.)
2. The Letsfit app is closed on the phone. (This can occur automatically under certain circumstances.)

To reconnect the watch to your smartphone, please kindly take the following steps:

1. Go to your smartphone system Settings ⚙️, find the Letsfit app, and enable the Location ? and Bluetooth ?.
2. Clear all running / background processes on your smartphone. Open the Letsfit app, go to the "Settings" page, tap "EW4", and then the watch will reconnect to your smartphone and update data. You can also restart your smartphone and Bluetooth ?, then re-pair the watch in the app.

Blood Oxygen Level Measurement Accuracy

The Blood oxygen level will be affected by factors such as motion, watch placement on the wrist, skin temperature and skin perfusion. These factors will cause fluctuations in blood oxygen measurements.

For a single measurement on the watch, please wear the watch a finger-width below the wrist bone, snug but comfortable on your wrist. When measuring, stay still and make sure your wrist is flat with the watch facing up. If you are sitting, you can rest your arm on a table with the watch facing up.

The smart watch blood oxygen sensor isn't a medical device and won't be able to diagnose or monitor any medical conditions. If there is a problem with the measurement, we recommend you consult your doctor.

Warranty

We strive to build our products with the highest attention to detail and craftsmanship. However, sometimes there are occurrences of a defect, so we are happy to offer a ONE-year hassle-free warranty on all our devices as we continue to make amazing products. Please contact us if you have any questions about our devices.

Important Safety Instructions

General Safety

• The device contains electrical equipment; improper use may cause injury. Prolonged contact may contribute to skin allergies.
• Do not expose the device to liquid, moisture, or rain while charging. Do not charge when wet, as this may result in electrical shock and injury.
• Consult your doctor before use if you have preexisting conditions that might be affected by this device.
• Do not expose your watch to extremely high or low temperatures or near open flames (stoves, candles, fireplaces).
• This product is NOT a toy. Keep out of reach of children and pets. Small parts may cause choking if ingested.
• Never attempt to abuse, crush, open, repair, or disassemble the device. Doing so voids the warranty and can create a safety hazard.
• If parts require replacement, contact us.
• Do not use the device in a sauna or steam room.
• Dispose of the device, battery, and package according to local regulations.
• Always be aware of your surroundings. Do not check notifications, GPS, or other information while driving or in situations where distractions could cause injury or hazard.

Battery Warnings

• The device uses a lithium-ion battery. Improper handling can lead to shortened battery life, fire, chemical burns, electrolyte leakage, or injury.
• Do not disassemble, modify, remanufacture, puncture, or damage the device or batteries.
• Do not remove or attempt to remove the non-user-replaceable battery.
• Do not expose the device or batteries to fire, explosion, or other hazards.

Health Warnings

• If you have a pacemaker or other internal electronic device, consult your physician before using the heart rate monitor.
• The optical heart rate monitor emits green light and flashes occasionally. Consult your physician if you have epilepsy or are sensitive to flashing lights.
• Always consult your physician before beginning or modifying any exercise program.
• The device, accessories, heart rate monitor, blood oxygen level measurement, and related data are intended for recreational purposes only and are not medical devices. They are not intended to diagnose, monitor, treat, cure, or prevent any disease or condition.
• Heart rate and blood oxygen readings are for reference only. No responsibility is accepted for erroneous readings.
• While the optical heart rate monitor technology provides an estimate, inherent limitations may cause inaccurate readings due to user characteristics, device fit, or activity type/intensity.
• The watch relies on sensors that track movements and metrics. Data provided is an estimation and may not be completely accurate (e.g., steps, sleep, distance, heart rate, blood oxygen, stress, calories).

Safety Instructions for Skin Irritation

• If you experience discomfort or skin irritation, try cleaning the device. Residue or foreign materials may aggravate your skin. Ensure the watch is worn correctly.
• Caution: If skin irritation occurs, refrain from wearing the watch for 2-3 days. If symptoms persist or worsen, consult a physician.
• Individuals with eczema, allergies, or asthma may be more likely to experience skin irritation or allergy from a wearable device.

Clean your watch

• Clean your wrist and watch band, especially after exercising or sweating. Use fresh water, wipe with rubbing alcohol, and dry thoroughly.
• When using sunblock, lotion, or oil, clean the watch with a soap-free detergent, rinse, and dry thoroughly.
• If the watch gets stained or contains foreign materials, wipe with a moistened, soft bristle toothbrush.
• Avoid soap, cleaning agents, abrasive materials, or compressed air for cleaning.
• Skin irritation can be caused by residues from cleaning agents.
• Do not clean with ultrasonic waves or external heat sources.
• Moisture or substance build-up on the back of the watch can slow charging, cause inaccurate heart rate measurements, and skin irritation.

Keep your watch dry

• To prevent skin irritation, keep the watch dry. Dry thoroughly with a clean, soft cloth if wet. Dry the charging surface before attaching a charger or wearing.
• If you sweat for more than two hours, wash your band and wrist to avoid irritation.
• Prolonged rubbing may irritate skin; take breaks by removing the watch regularly.
• If exposed to liquids other than fresh water (e.g., salt water), rinse immediately with fresh water and dry thoroughly.
• To minimize damage, avoid direct contact with sunscreen or insect repellent sprays. Remove watch while applying these.

Wear your watch properly

• For all-day wear (not exercising): wear horizontally, a finger's width below your wrist bone, lying flat.
• When exercising: wear higher on your wrist (about 2-3 finger widths above wrist bone) to improve heart rate signal due to increased blood flow.
• Do not wear too tight; it should be loose enough to move back and forth. For exercise, it should be slightly tighter (snug but not constricting) than for all-day wear. Loosen after exercise.

Maintenance

• Regularly clean your wrist and watch, especially after sweating or exposure to substances like soap or detergent.
• Use soapless detergent, rinse thoroughly, and wipe with a soft towel or napkin. Do not use household cleansers.
• While water-resistant, wearing a wet band is not good for your skin.
• If bands get wet (sweat, shower), clean and dry them thoroughly before wearing. Ensure skin is dry before putting bands back on.
• Avoid contact with sharp objects to prevent scratches.
• For light-colored bands, minimize contact with dark clothing to prevent color transfer.