Wireless RC Switch * * RF Technology works through walls * * Easy Installation ? Add more lights to * * same remote switch ? Auto shut-off timer * * 2 AAA batteries (not included) * * Up to 20 Remote Control Lights can be linked to this switch. It can be programmed to work in existing sets, or used in up to eight different ones. It operates up to 60 feet, penetrates walls, and automatically shuts off the lights if they are inadvertently left on.