MaterialCarbon SteelPackage Content1 x Collet Chuck WrenchDimensionOpening Width: 30mm / 1.18"; fit For: ER20A Clamping Nut.Overall Size: 165mm/6.5" x 60mm/2.4" x 5mm/0.2"( Max.L x Max.W x T)Product Features- 1.Anti-slip Handle - The red handle of our clamping nut wrench is ergonomic, anti-slip and wear-resistant. Designed to hold the wrench tightly and save on the amount of work required.- 2. Nice Process - The surface of this wrench is treated with special technology, high hardness and wear resistance, making the surface easy to keep clean and not easy to rust.