The X10 Slimfire Wireless Keychain Remote works with an X10 wireless transceiver and controls two X10 receiver modules independently. The remote sends On/Off and Dim/Brighten commands to Unit Codes 1 and 2. It"s easy to program, easy to use, and small enough to fit on your keychain! NOTE: Requires an X10 transceiver or wireless security system base receiver (sold separately).