Smart Skimmer Security by AutoAqua uses the uniquely-designed contactless optical sensor to prevent the protein skimmer from overflows. No moving parts to service or fail. Magnetically coupled sensor makes it super easy to install and adjust the desired level on the collection cup. No need to purchase new lids or modifications to the collection cup are needed for installation. As the level in the cup goes too high, Smart Skimmer Security will shut down the skimmer immediately to prevent your skimmer from overflowing. Auto time delay function prevents false alarm due to power outages.