Feature: 1. EFFECTIVE VIBRATION SUPPRESSION: Made of 40Cr material, effectively suppressing vibration, has high concentricity and stable processing 2. FULLY FORMED INSIDE AND EXTERIOR: The inside and outside of the door -tool are formed in one piece. Fine control processing brings more stable performance and high concentricity 3. LONGER SERVICE LIFE: After inner hole ground processing, suitable for high precision machine tool processing and has longer service life than ordinary tool holders 4. HIGHER HARDNESS: Using carburizing and quenching process, the hardness is higher, the fatigue resistance of the interface is stronger and more durable 5. TIGHTENING RANGE 1-7MM : Clamping range is 1-7mm, has stable structure, excellent performance and long service life Specification: Item Type: Collet Chuck Holder Product Material: 40Cr + Carbon Steel Hardness: 45 -46HRC Head Diameter: Approx. 19mm/0.75in Clamping range: approx. 1~7mm/0.04~0.28in Adapter Collet: ER11 Thread Type: A Tool Handle Diameter: Approx. 12mm/0.47in Package List: 1 x Collet Chuck Holder 1 x Wrench Note: 1. Incorrect assembly may damage the precision of the nut and spring. 2. Only the corresponding collet chuck can be used to assemble the nut. 3. Do not tighten tools that exceed the tightening range.