The Lawn Genie 3/4 in. anti-siphon valve manually activates zone sprinklers with the simple turn of a handle and provides optimum performance even in potable or dirty water conditions. This easy to use anti-siphon valve also offers a jar-top bonnet for convenient access to diaphragm for quick maintenance inspections. Designed to protect drinking and other household water from contamination, this valve also features unique built-in prevention.