Pneumatic Universal Interchange Male Coupler SKU Body Size Threads Material Length OD Hex Inch HFUC-251-4MP 1/4 1/4-18 NPT Brass 2.44 0.92 3/4 HFUC-251-6MP 1/4 3/8-18 NPT Brass 2.44 0.92 3/4 HFUC-371-6MP 3/8 3/8-18 NPT Brass 2.64 1.09 15/16