1. Porcelain insulator 2. post type, Disk type 3. color of white, gray, blue, brown 4. According to IEC, GB, ANSI, BS ... type insulator, post type, Disk type and all kinds of ceramic insulators use on transformer, fuse cutout, surge arrester.Surface ... of insulator available color of white, gray, blue, brownAccording to IEC, GB, ANSI, BS, JIS, AS,DIN. porcelain insulator/ceramic insulator 57 series