Npt Thread: 3/4" Npt x 14 Tpi Female (Actual Nominal Thread Size 1-1/16") to Npt Thread: 3/8" Npt x 18 Tpi Female (Actual Nominal Thread Size 5/8") Material: Brass Type: Reducing Pipe Coupling Product Description IMPORTANT NOTE: "Pipe Thread/NPT Size" DOES NOT directly correspond to Actual Dimensions of the thread (conversion is required). If you have any questions regarding sizing please contact us and we'll be happy to assist in providing measurement assistance.Quantity: 1 (One) pieceOur quality barbed/threaded connectors/couplers are manufactured FasParts' highest standards. They are perfect for connecting lines for air, water, fuel, oil and inert gases.Working Pressure for up to 1000 PSI @ -65F to +265FSuitable for use in Automotive, Nautical, Industrial, and Commercial applications This precision product works great with other quality FasParts accessories.