this ceramic insulator is according to the ANSI C29.2. the Applicable standard of my insulators:ANSI, GB, IEC, AS, BS,etc. Class ANSI52-1 XP-4.5C-M52-2 XP5-7C-M52-3 XP-7C-M52-4 XP-7C-M52-5 XP-11-M52-6 XP-11-M52-8XP-16C-M 52-9XP6-4.5C-M52-10 XP-16C-MFig123434354Main Dimensions(mm)D165190.5254254254254279.4114279.4H139.7146146146146146146160165Creepage Distance/mm177.8209.5292292279.4279.4279. ...