AKG WMS420 INSTRUMENTAL Uhf Wireless Instrumental SystemThe AKG WMS420 UHF Wireless Instrumental System is designed for live sound reinforcement applications such as for public address, presentations, installations, and performances that require up to eight simultaneously operating systems over a 30 MHz bandwidth. This system consists of a PT420 Beltpack Wireless Microphone Transmitter, an SR420 UHF Stationary Wireless Receiver, two detachable RF antennas, an AC adapter for the receiver, a AA size battery