Rain Bird JTVAS075 Jar Top Anti-Siphon Valve, 3/4" Threaded Female x Female (Discontinued by Manufacturer replaced with model # DASASVF075) This valve model was Discontinued By Manufacturer, search for new model DASASVF075 with Amazon ASIN B00004RAAZ Jar Top lid quickly unscrews without tools allowing easy access to diaphragm for effortless maintenance and cleaning Installed above ground and will prevent back flow if properly installed Operates automatically or manually with manual bleed screw Reverse Flow design reduces stress on diaphragm for dependable operation Energy efficient, low power encapsulated solenoid with captured plunger