1" NPT Inlet/Outlet Adaptor Aluminum Fits Non-Ad with a 3.70 diameter 1-12 UNF 3/4" Flow (Aluminum) PetroClear Aluminum Heads are epoxy impregnated. APPLICATION: 40502/10/30 P, 40510 A, 40510 D, 40510/30 W, 40810/30 P-DV, 40910/30 P, 40910/30 W