EJEAS MS20 Mesh 3.0 Group Intercom Communication System Motorcycle Helmet Bluetooth 5.1 Headset with CVC Noise Cancelling for 20 People Speaking Full Duplex at the same time (2 Pack)Advanced Network Technology: The MS20 motorcycle network interface uses the latest MESH technology, can be automatically reconnected after separating it into an effective range, solves the problem of separation while driving with other Bluetooth interfaces, the maximum distance between two people for the MS20 network interface can reach 1. 8, and the intercom distance between 20 people can reach 3 people 3. 8 1 mi Up to 4 . 5 km size. Size M FM voice