1. Touch the Bluetooth-compatible button with your finger to control the multimedia playback without touching your phone. 2. Can control multimedia playback, pause and track forward and backward, and can also adjust the volume of mobile phone ringtones and multimedia playback volume. Even if you put your phone in your pocket or wallet, you can operate it within an effective distance of 12 meters. 3. Good compatibility:For iOS devices, support Bluetooth-compatible 3.0 or higher, For Android device, support Bluetooth-compatible 4.0 or higher 4. Compact design with a diameter of 35mm. Battery: CR2016 button battery Size: 35mm/1.38inch in diameter Instructions: 1. Make sure your phone's Bluetooth-compatible is turned on. 2. Press and hold the pairing button to pair until the indicator light turns blue and flashes. 3. Check if "Bluetooth-compatible Media button" already exists in the device list. 4. Select "Bluetooth-compatible Media button" and wait for the -up menu. 5. Click the "pair"