The AKG WMS420 UHF Wireless Headworn Microphone 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 for the transmitter, and a C555 L headworn microphone.

The UHF receiver features two detachable antennas that enable connection to a wide range of professional RF accessories such as antenna splitters and remote mounted directional antennas for use with multi-channel systems. The front panel of the receiver features an on/off button, a rotary volume control, a button for selecting one of the available eight carrier frequencies within the system's range, an LCD display that shows the selected receiving channel, an RF OK LED to indicate the presence of a signal, and a CLIP LED to indicate when the audio level is too high.

The back panel of the receiver features a squelch control knob that will automatically mute the audio output if the strength of the radio transmission frequency becomes too weak. The back panel also features a DC IN port with strain relief for connecting the AC adapter, a balanced XLR-3F output for connecting to a live mixer, and an unbalanced 1/4" output for connecting to a guitar or instrument amplifier.

The beltpack wireless transmitter comes with a C555 L headworn microphone, but will also work with any of AKG's line of MicroMics. The beltpack features a noiseless on/off/mute switch, a gain control knob, and an LED indicator light. The transmitter is powered by a single AA battery which provides between six and eight hours of operating time with a range of approximately 30 meters. The transmitter also includes charging contacts for use with rechargeable batteries and AKG's CU400 rechargeable base station (sold separately).