ER SPANNER(ER WRENCH) 1.material:spring steel 2.collet, chuck, cnc tool,tap ... holder, cutting tool, MT adapter are available ER SPANNER(ER WRENCH)1.Specifications incl uding:S/ER11 S/ER16 S/ER20S ... of machine tool accessories.Production includes milling chuck series,CNC tool series,collet series,boring heads series,etc.Sales covering the USA,Germany,Britain ...