Dixon SHD-Series Schrader Pneumatic Female Pipe Twist-Lock Coupler SKU Body Size Threads Length 2SHDF2 1/4 1/4-18 NPT 2.10 2SHDF3 1/4 3/8-18 NPT 2.18 4SHDF3 1/2 3/8-18 NPT 2.59 4SHDF4 1/2 1/2-14 NPT 2.66 4SHDF6 1/2 3/4-14 NPT 2.81