Anti-Drain-Back Valve, Thread Spec: 3/4" x 16 NPT (191mm x 4064mm) Backed by Sierra's industry leading warranty Engineered with premium grade materials that will excel in the extreme marine environment Epoxy coated for corrosion resistance, Heavy-wall steel canister for further corrosion protection High-efficiency filter media that meets or exceeds the OE's filtration Fits : V-225 hp (V-6) FourStroke O/B