Specification: Bluetooth: 2.4GHz Bluetooth 3.0 + EDR; Frequency response: 20~20,000Hz; Transfer Distance: 33FT/10M(No walls between the cellphone and this bluetooth headset, otherwise it may cause delay of the bluetooth signal); Play/Talk:10hours; Easily charge via USB port; Low battery notification; Volume +/- button; Track Forward/Backward; Buttons adjustable; Built-in Microphone, answer to the phone calls when paired with mobile phone; Size:175 x 200 x 45mm; How to use: Power on: keep pressing multifunctional key until you see the blue LED shine; Power off: keep pressing multifunctional key until you see the red LED shine; Pairing: First, please make sure the headset is power off and the Bluetooth devices is within 10m; Second, press multifunctional key for 5-6 seconds until blue and red LED shine by turn; Third, activate Bluetooth of the device you want to pair, search and select Headphone Device in the Bluetooth list. Fourth, after pairing succeed, the blue LED of the headset shines twice or three times every 4 seconds.