Pooleye Alarm For In-ground Pools Protection For Your Family P/N: PE21 About the product: Built in pool water and air temperature monitor With Remote Receiver. Adjustable Sensitivity. Eliminates False Alarms. Ladder or Deck Mount. Underwater, the rudder switch inside the protective cage floats vertically, undisturbed by wind or rain on the surface (primary causes of false alarms). When an object enters the water, the rudder switch is moved off-center by the action of the underwater waves, triggering the alarm.