The Sennheiser SK 100 G4-AS Wireless Bodypack Transmitter (626 - 668 MHz) is the latest addition to their evolution family of wireless microphones. It features true diversity technology and can be used when paired with a companion receiver and microphone, as part of a wireless RF transmission system for live stage, theatre, presentation, and rehearsal applications. The transmitter features 1680 frequencies tunable in 25 kHz steps with 20 fixed frequency banks and up to 12 compatible frequency presets. There is 1 user bank with up to 12 user programmable frequencies. The transmitter's menu-driven backlit display shows current frequency, frequency band and channel number, metering of AF level, transmission status, battery status, and more. Furthermore, the transmitter is equipped with a mute switch and is powered by two 1.5V AA size batteries or by one Sennheiser BA 2015 rechargeable accupack. It is built with a rugged metal housing. The SK 100 G4 transmitter will operate about 8 hours and is equipped with a 1/8" line/mic input jack. With 25 Hz to 18 kHz AF frequency response, the SK 100 G4 is designed to deliver a natural audio quality.