The compact water-resistant X10 4-Button Credit Card Controller is aptly named for its small credit-card style design. Keep it in your wallet or purse and conveniently control up to four X10 modules. Turn on/off devices connected to Appliance Modules dim/brighten lights connected to Lamp Modules trigger ActiveHome macros and more! FEATURES: Works with the X10 Deluxe Base Transceiver (TM751). Controls Appliance Modules and Lamp Modules. Operating range up to 100 feet. Water-resistant for use in rain or shower. SPECS: In the default state (after first fitting the battery) the Controller is set to Housecode A. The first (top) two ON/OFF buttons control modules set to Unit Code 1. The second two buttons control A2 the third A3 and the fourth A4.