The Azden WLT/PRO VHF Wireless Bodypack Transmitter consists of the WM-Pro bodypack transmitter and EX-503 omnidirectional lavalier microphone. The transmitter features 2 switchable VHF channels (169.445 MHz and 170.245 MHz) and is compatible with all Azden "PRO" series VHF receivers. The WLT/PRO is powered by a single 9V battery and includes a belt clip.