* Industry first Mesh intercom with Multi-Hop for infinite rider pairing * Up to 1.2km (.75 mile) per person. * Industry first crash detection & contact alert: USAFE advanced accelerometer detects hard impacts. If you are unresponsive, USAFE can alert emergency services and contacts your status and GPS location. | Article: UCLEAR Motion Infinity Bluetooth Communication System Double Set, black | Article: UCLEAR Motion Infinity Bluetooth Communication System Double Set, black, black, Size One Size