Make any switch wireless! Plug your capability switch into this transmitter and it will control any switch adapted device that is plugged into the receiver module. For example, if a tape player is plugged into the receiver module, it can be remotely turned on/off by the switch of your choice. Receiver size: 6"L x 4"W x 2"H, Transmitter size: 4"L x 2½"W x 1"H. Receiver requires 4 AA Batteries and Transmitter requires 2 AAA Batteries.