Built-in atmospheric backflow preventer protects household water supply from possible contamination. Safe low voltage solenoid provides long-lasting service. Flow control allows for precise adjustment after installation. Manual external bleed allows for operation without electrical power. Double-beaded diaphragm. Self-aligning bonnet. 18 in solenoid lead wires for easy access and installation. Anti-siphon valve with flow control (thread) previously RJ711.