Check the listing for details. Optex Wireless 2000 Chime Box With Relay (RC-20U). Color: N/A, Condition: New. Listed at 83.54 USD. The Optex RC-20U Wireless 2000 Chime Box With Relay is the heart of the Optex "Wireless 2000" annunciator system. It sounds alerts when it receives wireless signals from up to 9 motion-activated sensor transmitters. It is ideal for both home and business use.No more surprises! Wireless 2000 monitors your property 24 hours a day to detect approaching vehicles and people, giving you time to prepare.No more missed visitors or deliveries! Wireless 2000 serves as a welcome chime or perimeter alert for your home or shop.No more hard to reach switches! Wireless 2000 works as a convenient wireless switch for activating a variety of electric equipment (e.g. doorstrikes / magnetic locks, lights, sirens, motors).Simple, automated set-up: Setup is simple! Just two buttons perform all set up functions.More than 8 million codes:Transmission codes are preset by the factory with over 8 million possibilities, virtually eliminating the possibility of interference or crosstalk. Note: Motion-activated sensor transmitter is required to complete a Wireless 2000 system.Technical DetailsMPN: RC-20UUPC: 788924040219Design VersatilitySpecially designed sensor mounts easily on walls, ceilings, fenceposts, desktops, etc.Weatherproof design of sensor allows outdoor use.Two detection patterns: 50ft Long Range and 17ft. Fan PatternDetection pattern adjusts easily for perfect aiming.Receivers mount on wall or desktopRC-20U Chime Box with RelayAccepts 9 transmitters, identifies each group of three with different chime toneOperates with 9VDC adapter (included)Wall mount or table mount designForm C relay for activating other devices (50V AC 1A max, ot 24V DC 1A max) with adjustable output duration