UHPPOTE Wired Water Probe Liquid Overflow Leak Induction Electrode Detector Switch Singal Sensor for Alarm System (Pack of 2 Pairs) Case Material: ABS; Detecting Leads Material: Stainless steel Controller and switch not included, should buy separate Suit for: Water tower, return pipe, water heater, computer facilities, machine platform,electrical control room, central air conditioning studio, factory, warehouse, file reference room,office, basement, laboratory, fish bowl, water tank, pool, water dispenser, air conditioner Once water get in touch with the stainless steel probe, The circuit will be switched on and convey a signal to the alarm device. Attention: Controller and switch not included, should buy separate