Design Product color: Black Efficiency Maximum range: 1000 m Bluetooth profiles: HFP Device software updates: Yes Headset mode: Yes Automatic volume control: Yes Bluetooth version: 5.1 Package contents Number of pieces: 1 Quick Start Guide: Yes Cables: USB Type-A to USB Type-C Mounting kit: Yes Battery Battery life: 15 hours Charging time: 2.5 hours Rechargeable battery: Yes Safety warning Warnings Do not use near sources of heat or fire. Keep away from children. Check the condition of the batteries regularly to prevent leakage.