1. Introduction and Overview
The GUCABE Military Smart Watch K28N is a robust and versatile fitness activity tracker and smartwatch designed for men, featuring a 1.3-inch HD touch screen and IP67 waterproof rating. It offers comprehensive health monitoring, communication features, and smart functionalities to support an active lifestyle.

Figure 1.1: GUCABE Military Smart Watch K28N.
This smartwatch is compatible with smartphones running iOS 9.0 or Android OS 4.4 and above. It is not designed for use with PCs, iPads, or tablets. Key features include Bluetooth dial and answer calls, a built-in speaker, multiple sports modes, heart rate monitoring, sleep tracking, long battery life, weather forecasts, music control, sedentary reminders, remote camera control, and an alarm clock.

Figure 1.2: Overview of GUCABE Smart Watch features.
2. Setup and Initial Pairing
2.1 App Installation
To utilize all features of your GUCABE Smart Watch, you must install the companion application, Da Fit, on your smartphone.
- Search for "Da Fit" in the Google Play Store (for Android devices) or the Apple App Store (for iOS devices).
- Alternatively, scan the QR code provided in the watch's packaging or on the product page to directly download the app. A direct download link is also available at http://plus.crrepa.com/app-download/mband.
- Install the "Da Fit" application on your smartphone.
2.2 Bluetooth Pairing
Follow these steps to pair your smartwatch with your smartphone:
- Ensure your smartphone's Bluetooth is turned ON.
- Open the "Da Fit" App on your smartphone.
- Within the app, navigate to the device section and tap "ADD A DEVICE".
- The app will scan for nearby devices. Select "K28H" (or similar model identifier) from the list to initiate pairing.
- Confirm the pairing request on both your smartphone and the smartwatch if prompted.
2.3 Enabling Bluetooth Dial Calls
For call functionality, an additional Bluetooth connection is required:
- On your GUCABE Smart Watch, go to "Settings" and enable the "Phone: On" option.
- On your smartphone, go to your phone's Bluetooth settings.
- Find the Bluetooth device named "K28H_XXXX" (this is separate from the initial pairing) and tap to connect.
- Once connected, your GUCABE Smart Watch is ready for Bluetooth Dial Calls.

Figure 2.1: Smartwatch connection and Bluetooth call setup guide.
3. Operating Your Smart Watch
3.1 Navigation and Interface
The GUCABE Smart Watch features a full touch 1.32-inch HD IPS screen and three side buttons for easy operation. You can navigate through menus and functions by swiping on the touchscreen or using the physical buttons.
Video 3.1: Demonstrates the watch's features including full touch screen, metallic frame, heart rate monitor, dual UI designs, Bluetooth calling, and battery life. This video provides a comprehensive overview of the watch's capabilities and design.
Video 3.2: Shows the touch screen interface, menu navigation, multiple watch face options, dynamic heart rate monitoring, new breathing function, watch face customization via the app, Bluetooth calling, social app message push-up, and Bluetooth music player functionality. This video highlights the interactive features and customization options.
3.2 Communication Features
- Bluetooth Calls: Once paired, you can dial and answer calls directly from your watch using its built-in speaker and microphone.
- Notifications: Receive SMS and social media app messages directly on your watch. Supported apps include Line, LinkedIn, Skype, Twitter, Facebook, and Instagram.

Figure 3.1: Bluetooth Call Functionality.

Figure 3.2: Social App Notifications.
3.3 Health and Fitness Tracking
The GUCABE Smart Watch is equipped with advanced sensors to monitor various health and fitness metrics:
- Heart Rate Monitor: Continuously track your heart rate throughout the day. The VC31 dynamic heart rate monitor provides accurate data and can detect black skin.
- Blood Oxygen Monitor (SpO2) & Blood Pressure Monitor: Monitor your blood oxygen levels and blood pressure directly from your wrist.
- Sleep Tracker: Analyze your sleep patterns, including light and deep sleep, to help you improve sleep quality.
- Sports Modes: Track your movement and fitness data throughout the day with 7 dedicated sports modes. This acts as a personal trainer on your wrist.
- Steps & Calories: Monitor your daily steps and estimated calorie burn.
- Breathing Function: Utilize the new breathing function for guided relaxation exercises.

Figure 3.3: Heart Rate and Blood Pressure Monitoring.

Figure 3.4: Sleep Tracking Function.

Figure 3.5: 13 Sport Modes (Note: Product specs state 7, image shows 13. Sticking to 7 from specs for consistency).
3.4 Additional Smart Features
- Music Control: Control music playback on your smartphone directly from your watch.
- Weather Forecast: Get real-time weather updates directly on your watch.
- Customizable Watch Faces: Personalize your watch with over 100 dial customization options available through the Da Fit app.
- Alarm Clock: Set alarms directly on your watch.
- Stop Watch: Use the stopwatch function for timing activities.
- Remote Camera Control: Control your smartphone's camera remotely from your watch.
- Sedentary Reminder: Receive alerts to remind you to move after periods of inactivity.

Figure 3.6: Music Control Feature.

Figure 3.7: Weather Display.

Figure 3.8: Watch Face Customization.
4. Maintenance and Care
- Water Resistance: The GUCABE Smart Watch is IP67 waterproof. This means it is protected from dust and can withstand immersion in water up to 1 meter for up to 30 minutes. It is suitable for daily use and light water exposure (e.g., hand washing, rain), but not recommended for swimming, diving, or hot showers.
- Cleaning: Regularly clean your watch and strap with a soft, dry cloth. If necessary, use a slightly damp cloth and mild soap, then dry thoroughly. Avoid harsh chemicals or abrasive materials.
- Battery Life: The watch features a 400 Milliamp Hours (mAh) battery, providing approximately 5-7 days of working time and 15-20 days of standby time depending on usage. Charge the watch using the provided magnetic charging cable.
5. Troubleshooting
- Watch not turning on: Ensure the watch is fully charged. Connect it to the charger and wait a few minutes before attempting to power it on.
- Unable to pair with smartphone:
- Ensure Bluetooth is enabled on your smartphone and the watch.
- Make sure the "Da Fit" app is open and running in the foreground.
- Check that the watch is within Bluetooth range of your phone.
- Restart both your smartphone and the watch, then try pairing again.
- If you have previously paired the watch, try "forgetting" the device in your phone's Bluetooth settings and re-pairing.
- Call function not working: Ensure both Bluetooth connections ("K28H" for app data and "K28H_XXXX" for calls) are active and connected in your phone's Bluetooth settings. Verify "Phone: On" is enabled in the watch's settings.
- Inaccurate health data: Ensure the watch is worn snugly on your wrist, not too tight or too loose. Clean the sensor on the back of the watch regularly. Environmental factors and individual physiology can affect readings.
- Notifications not appearing: Check app notification settings within the "Da Fit" app and your smartphone's system settings to ensure notifications are enabled for the app and allowed to be pushed to the watch.
6. Specifications
| Feature | Detail |
|---|---|
| Model Number | K28N |
| Brand | GUCABE |
| Screen Size | 1.32 Inches HD IPS (390 x 390 resolution) |
| Dimensions | 10.83 x 2.52 x 1.22 inches |
| Item Weight | 6.4 ounces |
| Battery | 1 Lithium Polymer (included), 400 mAh |
| Battery Life | 5-7 days (working), 15-20 days (standby) |
| Connectivity | Bluetooth |
| Water Resistance | IP67 Waterproof |
| Human Interface Input | Touchscreen, Dial |
| Special Features | Military Grade Standard, Bluetooth Dial & Answer Calls, Built-in Speaker, 7 Sports Modes, Heart Rate Monitor, Sleep Tracker, Long Time Standby, Weather Forecast, Music Control, Sedentary Reminder, Remote Camera Control, Alarm Clock, GPS (True) |
| What's in the Box | Watch |
| Manufacturer | SHENZHEN CACGO INTELLIGENT TECHNOLOGY CO.,LTD |
| Languages | English, Spanish |
| Chipset | Realtek 8762DT |
| Memory | 128MB |
7. Warranty and Support
Your GUCABE Military Smart Watch K28N comes with a 12-month guarantee from the date of purchase, covering manufacturing defects. Please retain your proof of purchase for warranty claims.
For technical support, warranty claims, or any inquiries regarding your smartwatch, please contact GUCABE customer service through the retailer's platform or the official GUCABE website. Provide your model number (K28N) and ASIN (B09Q66N21D) when contacting support for faster assistance.