Light shows the position of the toilet seat. When the toilet seat is down, the light is green; and when the toilet seat is up, it is red. Sensor Position is behind LED light Power: 2pcs AA battery (Not included) Color: White size, 3.5 in. X 3 in. X 1.5 in. Weight: 2.5 oz. Light will mount on any flat service. Great for closets, Drawers or a small room.