1. Bluetooth is compatible with V5.0 wireless helmet headset, with high fidelity stereo, and supports stable and fast signal transmission within 10 meters. Built-in high sensitivity microphone, windproof sponge cover, improve sound quality. Due to low power consumption, 180mAh lithium battery can support 8 hours of continuous music time (100 volume) per charge. This hands-free helmet headset supports automatic answering, voice assistant (compatible with Siri), English voice prompt when turning on, off, pairing, maximum volume and low battery power, and has an ultra-safe riding experience. You can check the remaining battery power of your phone. It is suitable for most motorcycle helmets and can be easily installed with the attached hook and loop fasteners. BT: V5.0+EDR/A2DP/AVRCP/HFP frequency: 2.4026GHz - 2.480GHz channel: StereoSNR: 112dB voice assistant: lithium battery support: 3.7V/180mAh Usage time: 8 hours standby Package content: 1 x helmet headset, 1 x charging cable Note: Light reflection and different display may cause the color of the items in the picture to be slightly different from the real items. The allowable error of measurement is+/- 1-3cm.