... all round the world.ZHY CNC Tools ER20M Wrench Manufacuturer1.Three ER Wrench: type A, type M, type UM.2.Using SCM- ... used to tool holders, to tighten the tool.4.ER A type wrench: ER11A-BS, ER16A-BS, ER20A-BS.5.ER ... UM type wrench: ER25UM-BS, ER32UM-BS, ER40UM-BS, ER50UM-BS.6. ... ER M type wrench: ER8M-BS, ER11M-BS, ER16M-BS, ER20M-BS, ER20M ...