Caymuller DT628
Caymuller Bluetooth Headset User Manual
Model: DT628
Introduction
Thank you for choosing the Caymuller Bluetooth Headset. This headset is designed to provide clear audio and reliable wireless communication, featuring Bluetooth 5.1, advanced noise cancellation, and multi-point connectivity. It is ideal for various applications including phone calls, online meetings, and music listening, offering comfort for extended wear.
What's in the Box
- Caymuller Bluetooth Headset (1 unit)
- USB Charging Cable (1 unit)
- User Manual (This document)
Product Overview

Figure 1: Caymuller Bluetooth Headset. This image shows the overall design of the headset, including the earcup, headband, and microphone boom.

Figure 2: Headset Controls. This image highlights the location of the LED indicator, Volume Up button, Volume Down button, and the Multi-Functional Button on the earcup.

Figure 3: 330° Rotatable Microphone. This image illustrates the microphone's ability to rotate, allowing it to be worn on either the left or right ear.
Setup
1. Charging the Headset
Before first use, fully charge the headset. Connect the provided USB charging cable to the headset's charging port and the other end to a USB power source (e.g., computer USB port, wall adapter). The LED indicator will show charging status. A full charge takes approximately 2 hours.
The headset provides up to 12 hours of continuous talk time and 160 hours of standby time on a single charge.

Figure 4: Battery Life. This image visually represents the headset's long battery life, indicating up to 12 hours of use.
2. Powering On/Off
- Power On: Press and hold the Multi-Functional Button for approximately 3 seconds until the LED indicator flashes blue.
- Power Off: Press and hold the Multi-Functional Button for approximately 3 seconds until the LED indicator flashes red and then turns off.
3. Bluetooth Pairing
- Ensure the headset is powered off.
- Press and hold the Multi-Functional Button for 5-7 seconds until the LED indicator flashes red and blue alternately. This indicates the headset is in pairing mode.
- On your device (smartphone, tablet, laptop), enable Bluetooth and search for available devices.
- Select "Caymuller DT628" (or similar name) from the list of found devices.
- Once connected, the LED indicator on the headset will slowly flash blue.

Figure 5: Device Compatibility. This image shows the headset's compatibility with various operating systems and device types, including iOS, Android, computers, and tablets.
4. Multi-Point Connection
The headset supports connecting to two Bluetooth devices simultaneously. This allows you to seamlessly switch between calls or audio from different devices.
- Pair the headset with the first device as described in "Bluetooth Pairing".
- Disable Bluetooth on the first device.
- Put the headset back into pairing mode and pair it with the second device.
- Once the second device is connected, re-enable Bluetooth on the first device. The headset should automatically connect to both devices.

Figure 6: Multi-Point Connection. This image demonstrates the headset's ability to connect to two separate Bluetooth devices at the same time.
Operating Instructions
Call Control
- Answer/End Call: Press the Multi-Functional Button once.
- Reject Call: Press and hold the Multi-Functional Button for approximately 2 seconds.
- Mute/Unmute Microphone: Press the "Volume +" and "Volume -" buttons simultaneously.
Volume Control
- Increase Volume: Press the "Volume +" button.
- Decrease Volume: Press the "Volume -" button.
Music Playback
- Play/Pause: Press the Multi-Functional Button once.
Voice Assistant (Siri/Google Assistant)
- Activate: Press the Multi-Functional Button twice quickly.
Wearing the Headset
The headset is designed for comfortable wear over extended periods. The microphone boom can rotate 330 degrees, allowing you to wear the headset on either your right or left ear according to your preference. Adjust the headband for a secure and comfortable fit.

Figure 7: In-Car Use. This image shows the headset being used by individuals in a car, emphasizing its suitability for mobile communication.

Figure 8: Versatile Applications. This collage illustrates various scenarios where the headset can be effectively used, such as video calls, driving, Zoom meetings, and call center environments.
Maintenance
- Cleaning: Use a soft, dry cloth to clean the headset. Do not use abrasive cleaners or solvents.
- Storage: Store the headset in a cool, dry place away from direct sunlight and extreme temperatures.
- Battery Care: To prolong battery life, avoid fully discharging the headset frequently. Charge it regularly, even if not in use for extended periods.
- Water Resistance: The headset has a waterproof rating, but avoid submerging it in water or exposing it to heavy rain.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Headset does not power on. | Low battery. | Charge the headset for at least 2 hours. |
| Cannot pair with device. | Headset not in pairing mode; Bluetooth off on device; too far from device. | Ensure headset is in pairing mode (flashing red/blue). Turn on Bluetooth on your device. Move headset closer to device (within 10 meters). |
| No sound or poor sound quality. | Volume too low; headset not connected; interference. | Increase volume on headset and device. Reconnect the headset. Move away from other wireless devices. |
| Microphone not working. | Microphone muted; incorrect audio input selected on device. | Press Volume + and Volume - simultaneously to unmute. Check device audio settings to ensure Caymuller headset is selected as input. |
| Multi-point connection issues. | Incorrect pairing sequence. | Follow the multi-point connection steps carefully. Ensure Bluetooth is re-enabled on the first device after pairing the second. |
Resetting the Headset
If you experience persistent issues, you may try resetting the headset. Consult the manufacturer's website or customer support for specific reset instructions, as this can vary by model.
Specifications
| Feature | Detail |
|---|---|
| Model Name | Bluetooth Wireless Headset |
| Connectivity Technology | Wireless (Bluetooth) |
| Bluetooth Version | 5.1 |
| Bluetooth Range | 10 Meters (33 feet) |
| Earpiece Shape | On Ear |
| Noise Control | Active Noise Cancellation (Microphone) |
| Battery Life (Talk Time) | Up to 12 Hours |
| Standby Time | 160 Hours |
| Charging Time | 2 Hours |
| Item Weight | 41 Grams (1.45 ounces) |
| Product Dimensions | 1.97 x 1.57 x 1.18 inches |
| Material | Plastic |
| Water Resistance Level | Waterproof |
| Compatible Devices | Cellphones, Tablets, Laptops |
| Control Type | Call Control, Touch |
Warranty and Support
This Caymuller Bluetooth Headset comes with an 18 MONTHS WARRANTY. For any product-related inquiries, technical support, or warranty claims, please contact our customer service. We offer 24 HOURS friendly customer online service to assist you.
Please refer to your purchase documentation or the official Caymuller website for specific contact details.
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