Specifications:Bluetooth Version: 5.0 Frequency: 2.402-2.480GHz Bluetooth Range: 20-30 meters Li-ion Battery: 3.7V/250mAh Charging Voltage: 5V Standby Time: 160 hours Working Time: 6 hours Charging Time: About 1.5 hours Temperature: -40℉~140℉ -40℃~60℃ Thickness of speaker:1cm(0.39inch) Diameter of speaker:4.15cm(1.63inch) How to pair with mobile phone?1.Manually pairing(at the frst time) Step 1:In the shutdown state,long press dialing button for 3 seconds,and tie red and blue lights of the LED indicator will flicker alternately to enter the bluetooth pairing state. Step 2:Open the bluetooth of the mobile phone,enter the bluetooth list,select the bluetooth name (BT Audio) and click to connect.The LED indicator light turns to blue and flashes slowly when the connection is successful. 2.Automatically re-pairing (after paired). If a cellphone has been paired with the headset before,it will be automatically re-paired when the headset is turned on again.If the phone and headset is out of efficient range,it will disconnect,but when it back to the efficient range, it will connect automatically again. 3.Automatically search The headset will be automatically into pairing mode again once the paired BT phone is off or inactive. Priority:Phone calls>Music,when there is a coming phone call,the playing music would suspend.After phone call,the music would resume to play automatically. Packing list1 x Helmet wireless headset 1 x Micro-USB cable 1 x User manual 2 x Magic paste