Accepts 9 transmitters and identifies each group of 3 with a different chime tonenOperates with 9VDC adapter (included)nWall-mount or table-mount designnForm C relay for activating other devices (50V AC 1A max. or 24V DC 1A max.)nInstall the Optex RC-20U Wireless Chime to enhance your Optex Wireless 2000 and 1000 systems. This wireless chime alerts you of a perimeter breach with three different chime tones. You can even program certain groups of transmitters to respond to differen