Take the fuss out of late night runs to the bathroom with the Toilet Tank Light Sensor. This unique light hooks right onto the toilet tank without needing any tools, and lights up the bathroom without waking up the whole house. Motion activated LED casts a soft, unobtrusive light every time you enter the bathroom so you can see what you are doing -yet is not too bright so you can't get back to sleep. The Toilet Tank Light with Sensor automatically shuts offonce you've finished. Uses 3 AAA batteries (not included). 8" X 1¾".