1.SIZE :From 1/2 to 48 (Seamless pipe fittings) From 26 to 72 (Seam pipe fittings) 2.STANDARD: AMSE,JIS ,DIN,GB ... .SIZE :From 1/2 to 48 (Seamless pipe fittings). From 26 to 72 (Seam pipe fittings)2.STANDARD: AMSE,JIS ,DIN,GB3 ... .000914.0266.7StdXS0.3750.5009.5312.7081.90109.00 steel Pipe Cap