This Transmitter emits a "toggle" command.
A Receiver will change states when it receives a "toggle" command.
If the Receiver is "On" when it receives a "toggle" command, it will turn "Off".
If the Receiver is "Off" when it receives a "toggle" command, it will turn "On".
The Large Switch Plate is designed to cover the hole in the wall left after a typical CDN/US wired switch has been removed.