The Bogen UBP800 Bodypack Transmitter & Lavalier Microphone are for use with the Bogen UDMS800 wireless microphone receiver. The UBP800 operates on 2 AAA alkaline or NiMH batteries features separate On/Off and Mute switches and a comprehensive display that alerts for low battery power and more. UBP800 UBP800 Bodypack Transmitter & Lavalier Microphone Feature Highlights: UBP800 Bodypack Transmitter & Lavalier Microphone, For Bogen UDMS800 Wireless, On/Off & Mute Switches, AAA or NiMH Battery Operation x2, Includes Lavalier Microphone, Adjustable Input Level