Features: With its patented design, this alarm detects objects fallen into the pool as light as 15 lbs! Patented Sub-Surface Propagation Wave Detector! Sensor Placed Below Water Surface Eliminates False Alarms Due to Wind, Rain! Deck Mounting System and Ladder Mounting System Included! Automatic Low Battery Check - Chirps Every 60 Seconds! EXTRA LOUD POOLSIDE ALARM Additional Information: Senses underwater waves, not surface disruption, eliminating most false pool alarms! When an object enters the water, the rudder switch is moved off center by the action of the underwater waves -- which triggers the alarm. Can be used under a solar blanket, and on pools up to 18' x 36' (650 sq. ft.)! Do-it-Yourself pool alarm has simple mounting kit included. Mount to coping, ladder or rail! This product is Brand New.