4 People Group Intercom: V4 Plus allows 4 sets of devices to connect at the same time in a maximum intercom range of 1500 meters. 4 riders can freely share the riding experience and enjoy the conversation. | Hands-free Communication: Connecting to the upgraded Bluetooth 5.1version, V4 Plus motorcycle Bluetooth interphone can automatically answer or reject calls within 5s. You could also listen to music and road conditions with FM radio while riding. | Advanced Noise Reduction Technology: With improved CVC noise cancellation technology, it reduces surrounding wind and background noise. You are allowed to enjoy Bluetooth stereo voice with high definition sound quality during riding at a high speed. | Large Battery Capacity: V4 Plus motorcycle helmet Bluetooth headset runs on a 750mAh large rechargeable battery. With just 2 hours of charging, the intercom working time can reach 18hours and the standby time can reach 150hours, suitable for long-time riding. | Waterproof and Compatibility: With IP65 waterproof, the headset could handle almost all weather conditions. It is compatible with full-face helmet, 3/4 helmet, flip-up helmet and most half-face helmets which can cover ears. The motorcycle helmet Bluetooth headset can withstand 14℉ to 122℉ and can be used in most countries and regions.