Rain Sensor -Nelson 8501 "RAIN TRIP" Hard Wired unit. Can be mounted with included bracket, or screwed onto 1/2" Conduit. Adjusts from 1/8" to 1" rainfall. Compatible with most controller brands (Ready for normally-closed or normally-open hookup) Supplied with 25 feet of hookup wire. Designed to be used with low voltage irrigation systems only. A water conservation product. Nelson and RAIN TRIP are trade names of L.R. Nelson, and have no affiliation with Yard-Boss web store.