Interstate Pneumatics CH640 3/8 Inch Industrial Steel Coupler 1/4 Inch Female NPT 3/8 inch Industrial Steel Coupler x 1/4 inch Female NPT NPT size: 1/4 inch NPT Female Temperature: -40 degree F to 212 degree F Seals: Buna-N (Nitrile) Ball Bearing: Quantity 6, stainless steel