This is an electronic shutoff switch kit for the Aquatec 6800 and 8800 booster pumps and includes the electronic shutoff (ESO) and the wiring harness. This switch connects to your incoming water line on your RO system and shuts off water to your system when your pump shuts off. This prevents unnecessary waste water from being produced, and replaces the auto shutoff valve in systems with a pump. The ESO features 1/4" quick-connect fittings and instructions and a diagram are include showing how to connect the kit to your current system. This must be used with a tank shutoff (TSO) switch or it will not work properly. If you need the entire shutoff switch kit, search in our other products.