The WM/T-PRO is a handheld microphone with a built-in transmitter. It transmits on the standard PRO frequencies (169.445MHz and 170.245MHz) and is compatible with all PRO Series receivers. The WM/T-PRO has a standby switch to mute audio and a rubberized coating to reduce handling noise. Runs on a single AA battery for up to 10 hours of continuous use.