Mini Syllable Wireless Cordless Bluetooth Headphone Earphone Headset with Mic for drivers (White) Battery Indicator: Red light is on during charging, blue light is on after complete charging. Its with A2DP/AVRCP high quality stereo audio transmission and remote control protocol. Driver: 8 mm environment friendly black magnetic design, phone talking is much clearer Bluetooth frequency range: 2.402-2.480GHz Audio frequency response80HZ-20 KHz