... all round the world.ZHY CNC Tools ER20M Wrench Manufacuturer1.Three ER Wrench: type A, type M, type UM.2.Using SCM-440 material, with ... to tool holders, to tighten the tool.4.ER A type wrench: ER11A-BS, ER16A-BS, ER20A-BS.5.ER UM ... -BS, ER32UM-BS, ER40UM-BS, ER50UM-BS.6.ER M type wrench: ER8M-BS, ER11M-BS, ER16M-BS, ER20M-BS, ER20M-BS ...