Black Bluetooth headset Characteristics Material: ABS+TPE Bluetooth Version: Bluetooth 5.0 Sensitivity: 103±3dB Frequency response: 20HZ ~ 8KHZ Maximum power: 3mW Impedance: 32Ω Battery capacity: 3.7V/55mAh Transmission distance: 10 meters Talking or music time: about 6 hours Supported protocols: HSP/HFP/A2DP/AVRCP Charging time: about 2 hours Supply voltage: DC 5V/0.3A The headset can be rotated so it can be worn in either the left or right ear Volume control keys