Product description: Name: MP100 Mono Bluetooth Headset Bluetooth version: Bluetooth 5.0 + EDR Support Bluetooth Protocol: A2DP, AVRCP, SPPP, HFP Battery: 50 mAh Track System: mono track Duration: about 4H Standby Time: about 50H Key Function Operation Power on: long press MFB button for about 3 seconds  Shutdown: long press the MFB key for about 4 seconds Pairing mode: long press the MFB key to turn on the machine and the pairing state will enter Answer: click the MFB key to answer the call  Hang up: click the MFB key to hang up the call  Rejection: long press the 1-2s MFB key during the call to reject the call Final redial: double click the MFB key to realize final redial  Play/pause: music state clicks MFB key to realize music play and pause Double click the MFB key in the unpaired state to switch between Chinese and English  Power prompt: low voltage alarm