Interstate Pneumatics CG660 3/8 Inch Universal Steel Coupler 3/8 Inch Female NPT 3/8 inch Universal Steel Coupler x 3/8 inch Female NPT NPT size: 3/8 inch NPT Female Temperature: -40 degree F to 212 degree F Seals: Buna-N (Nitrile) Ball Bearing: Quantity 6, stainless steel