The Basement Watchdog Universal Sump Pump Dual Float Switch was designed for reliability and flexibility. Its signature design feature, two floats for added protection and redundancy, is unique and unsurpassed in the industry. It has a protective cage that prevents debris from interfering with the floats, a solid top to keep out sand or dirt and a vented-curved bottom to prevent build-up under the float. Plus, superior engineering allow it to be compatible with most sump pumps. It is a piggy-back switch that is adjustable to any height. The primary float switch activates the pump when water raises the float by 1/3, the controller will then run the pump for an extra 10 seconds to drain excess water after the float switch drops. All of this ingenuity and it is very simple to install. If you want to be sure that your pump will turn on The Basement Watchdog Universal Dual Float Switch is your solution.