AirLine 99 Fitness is a wireless headset system designed for active performers and fitness instructors. The AH9 transmitter mounts directly to the included Qe headset, eliminating belts and cables. It offers up to 80 operating channels across 24 MHz and supports up to eight simultaneous systems per band, with a 300 ft line-of-sight range. The rugged CR99 receiver features true RF diversity, Group Scan, IR sync and an 8-hour rechargeable battery.