1/4" MNPT x 5/16" Barb Brass Anti-Siphon Valve | EVM-A/S 160-B-5/16 EVM A/S 160-B-5/16 Anti-Siphon Valve 1/4 in. MNPT x 5/16 in. Hose Barb Brass Anti-Siphon Valve 160 Series Designed to prevent the siphoning of marine fuel tanks should a fuel line leak or break occur Replaces OMC 173273