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.Honeywell