Honeywell Water Leak Alarm. Easy to use - set in lowest spot where water leak may occur. Detects water 1/16" deep. Ideal for use in areas not usually observed: Water Heaters - Behind Washing Machines or Dishwashers - Under Refrigerator for Ice Makers - Under Sinks - Sump Pumps of inside pits - Toilets - Behind or near media systems. Provides early warning of potentially costly water damage. One time use spot detector. Alarm sounds for up to 24 hours. Easy To use - set in the lowest spot where water leak may occur. Built in non replaceable battery included. Lasts up to 2 years. Unit must be replaced once alarm sounds.