... world.ZHY M And UM Type ER Wrench Hand Tool1.Three ER Wrench Hand Tool: type A, type M, type UM ... toughness.3.It is used to tool holders, to tighten the tool.4.ER A type hand tool: ER11A-BS, ER16A-BS, ... ER32UM-BS, ER40UM-BS, ER50UM-BS.6.ER M type hand tool: ER8M-BS, ER11M-BS, ER16M-BS, ER20M-BS, ... free to contact me, i will reply you at once, thank you! ZHY High Precision M And UM Type ER Wrench Hand Tool ...