Protect your home from water damage due to leaks, floods and seepage. An 85dB alarm sounds for up to 72 hours when the unit senses water—ideal for basements, garages or laundry rooms, near washing machines, water heaters, toilets and sump pumps. The sensor attaches to the bottom of the unit or can extend for 6 feet to a remote location (wall mountable). Uses one 9V battery (included). Plastic. 2 1/2" w x 4" h x 1 1/2" d.