Feature: 1. Fine Workmanship: Forged in vacuum quenching furnace to achieve carbon and oxygen co infiltration, increase hardness and enhance service life. 2. Centre Hole Design: The central through hole design can facilitate water cooling, effectively suppress vibration and increase shock resistance. 3. Universal Using: A square tool holder that can be used to hold tools of various diameters, which has good versatility and reduces processing costs. 4. Great Material: Made of premium 20CrMnTi, not easy to deform, also has excellent durability for long term use. 5. Easy to Carry: The box will largely simplify the storage and carrying as well, and the installation is very easy. Specification: Item Type: Collet Tool Holder Product Material: 20CrMnTi Product Model: TB16 16-ER16A Square Size: Approx. 16 x 16mm / 0.63 x 0.63in Product Length: Approx.127mm / 5in Application: Suitable for ER 16.. Package List: 1 x Collet Tool Holder1 x Storage Box