slip on flange,made of stainless steel. So Flanges:Standard: ASTM/ASME/ANSI, DIN, JIS, BS, ISO, GB/JB, etc.Size: 1/2"~48" or DN15~DN1200. Class: 125Lb~2500Lb, or PN2.5~PN250, or JIS5K~JIS40K. Materials: 304, 304L, 310S, 316, 316L, 317, 317L, 321, 347, 904L, S31803/2205/F51, S32750/2507/F53, etc. slip on flange