These long-lasting Manual Anti-Siphon Valves, designed primarily for residential use, offer simple operation and trouble-free performance in an operating range of up to 150 PSI 2700 Series 27pr IRRITROL 2706PR3/4" Manual Anti-Siphon Valve. Mfg. Irritrol 2706PR$9.98 IRRITROL 2709PR1" Manual Anti Siphon Valve Mfg. Irritrol 2709PR$11.23