AirLine AH7 Fitness Headset Transmitter is a lightweight wireless headset transmitter designed for AirLine 77 systems. It integrates the Qe condenser microphone into the headset, offering a bidirectional pickup pattern that reduces background noise and feedback. Powered by a single AAA battery, it delivers up to eight hours of operation and includes a power/low battery LED indicator and an internal power switch. The unit is channelized (K1–K6).