The ClapMaster™ is a box-shaped device that turns a plug on or off whenever you clap your hands... or, according to Roger, whenever a freighter warps by, or he coughs. Along with its apparent faults at responding to any random noise, it does not respond to voice commands, not even the word 'Clap', something Roger doesn't completely seem to understand. The Clapmaster™ requires a recursive-current subspace-grounded power outlet in order to function properly.
Roger's ClapMaster™ had a faulty pin, which got stuck in the socket. Roger comtemplated removing it with his bare hands, but that would've turned him into a Fried Roger. Instead, he actually managed to remove the pin using a pair of StarCon Pliers insulated with duct tape. He then managed to use the ClapMaster to disable the Bjorn leader, Nocuticles, and save the crew of the DeepShip 86.
The ClapMaster™ is a spoof of The Clapper, a similar product that is often made jokes about.