AirLine 77 AH7 Fitness Headset System combines a headset-mounted AH7 transmitter with the CR77 True Diversity receiver. The lightweight Qe condenser microphone is sweat‑resistant with bidirectional pickup, designed for high‑energy fitness environments. It offers up to 90 m (300 ft) line‑of‑sight range and provides balanced XLR and unbalanced 1/4" outputs. Transmitter runs up to eight hours on a AAA battery; AC adapter and 1/4" cable are included.