This set includes a WH30 Headset Mic, SLX1 Bodypack Transmitter and a SLX4 Diversity Receiver. The Shure Model WH30 is a light yet rugged headset microphone. Designed for vocalists and instrument-playing vocalists, the WH30 utilizes a high quality electret-condenser cartridge suitable for all applications where mobility, comfort, low microphone-visibility, and high sound quality are required. Because of its cardioid (unidirectional) pickup pattern, the WH30 provides isolation from extraneous sound sources and high gain-before-feedback. The SLX1 bodypack transmitter is designed to hold up to the most adverse conditions. Whether used with headworn, lavalier, instrument microphones, or with guitars or basses, the SLX1 is the definition of reliability. The SLX4 receiver brings unprecedented ease of use to wireless with Automatic Frequency Selection and Automatic Transmitter Setup.