Bluetooth i7 Headset with Mic listening to the song correct, support songs and call,remind call number, the last call back, all intelligent Chinese and English voice prompts, boot, pair, shut down the phone power will be low voice prompts; Power capacity will show on your Smartphones, you can see the power situation anytime, do not worry about the electricity ,make your life without worry;One to two connections, can be connected to two mobile phones at the same time Bluetooth headset connected to the phone after the shutdown , and then open the Bluetooth headset will connect back to the phone automatically , more convenient; Intelligent compatibility: support all Bluetooth mobile phone, tablet, notebook, singing it, QQ music, movies, etc. Specification Driver: 15mm Impedance: 32 OHM Bluetooth version: v4.1 Bluetooth + EDR Bluetooth bandwidth usage: 2.4 GHz Level of Power: CLASS II Output power: 30 mW Bluetooth distance: 10 meters without barriers Frequency Response: 20-20000Hz Operating voltage range: 3.0 V to 4.2 V Mitou sensitivity: -42dB With A2DP / AVRCP high-quality stereo audio transmission and remote control protocol Powerful noise de-noising circuit (active noise reduction) Switch between Chinese and English (start not connect Bluetooth status, press switch 2 times, hear switch tone successfully) Recharging time about 1 hour (charging indicator: red light, full power: red light out (blue light). Charge time: 2 hours, battery backup 3.5 hours