Specification： Bluetooth Version: 4.1 Support Agreement: HFP1.6, Headset 1.1, A2DP1.3, AVRCP1.5 Bluetooth transmission distance: 10 meters Playing/Talking time: 3-4 hours Standby time: 100 Hours Battery capacity: 40MAH Support incoming number calling Support 1 connect 2 function , Bluetooth can be connected to two mobile phone Package includes: 1*Bluetooth headphone (1 PCS earbud, not a pair) 1*USB Charging Cable 1*Silicone Ear Tips 1*User Manual 12 months worry-free warranty 24 hour dedicated Email customer support 100% customer satisfaction. Note: 1.The red light will come on when it is charging ,and change blue light when it is charged fully . 2.If you can\'t pair the bluetooth with your phone , please make sure this headset has been going into pairing mode. (Turn the bluetooth on and keep press the function key until the LED light flashing Red and Blue in turn ) 3.Keep away from all children,do not put in mouth or nose.