More Details: Button functions guide: Language switch: when turn on the headphone、 long press the "+" and "-" button until appear red and blue light flashing three times. Resume to default setting:  plug charger and press+\/- for 3s. Redial Lastest number: double click call button. Note: You can answer phone when take it from charger; Hang up the phone when put it on the charger.  Indicator light: Turn on: blue light flash twice. Pairing status: red and blue light flash alternately. Pairing Time: 90s Standby when connect to phone: blue flash every 7 seconds. Charging status: red light is always on. Fully charging: blue light is always on. Switch language: red and blue light flash for 3s at the same time.  Feature: Multi-point: Can connect to two devices at the same time. Switch songs and adjust volume. Support to display battery level on IOS system. Specifications:          General Specification             Brand Name        REMAX             Model Number        RB-T6C             Color        Black、 White、 Gold             Wearing Type        In-ear             Package Weight (kg)        0.2kg             Dimensions (mm)        30mm*20mm*57mm           Technical Parameters             Bluetooth Version        V4.0             Bluetooth Protocol        A2DP、 AVRCP、 HFP、 HSP             Transmission Distance        10m             Music Time        4 hours             Talk Time        4 hours             Standby Time        100 hours             Charging Time        2 hours             Battery         3.7V 50mA\/H             Battery Capacity        55mAh             Pairing Name        RB-T6C            Voice Language        English\/Chinese    Package  Included:                  1 X REMAX RB-T6C Headphone            1 X Charging Cable            1 X Manual