MH04 Helmet BT headset is specially designed for motorcycle helmets. It allows you to listen to stereo music by BT wireless connection and to answer the phone calls with Microphone. A perfect companion for motorcycle riders and ensures riding safety. Features: BT 5.0 brings high data transfer speed, stable connection and low power consumption. Wireless listen to stereo music with advanced BT 5.0+EDR technology. Hands-free function with Microphone and buttons, truly set your hands free. Built-in rechargeable Li-ion battery provides long standby and working time. DIY design, sticked to the helmet by magic tape, detachable and convenient to use. Sound reminder function, easy to set the device according to sound remind. Note: Please pay attention to the thickness of the headset (1.3cm for each). If the gap between your head and the helmet is too small, after sticking the headset on you may feel the squeeze of your ears. Specifications: Model Number: MH04 BT: V5.0+EDR, CSR Frequency: 2.402GHz-2.480GHz Transmission Distance of Microphone: 1 meter Li-ion Battery: 3.7V 180mAh Playback Time: about 8 hours (depends on volume level) Standby Time: 160 hours Charging Voltage: 5V Charging Time: 1.5 hours Color: Black Main Item Weight: 43g / 1.51oz Package Size: 18 * 10 * 2.5cm / 7.08 * 3.93 * 0.98in Package Weight: 91g / 3.2oz Package List: 1 * Helmet Headset 1 * USB Charging Cable 1 * User Manual ( English & Chinese)