Model: ER11. Gripping range: 1mm, , 2mm, 3mm, 4mm, 5mm, 6mm, 7mm. High clamping force, wide clamping range, high precision. Out tolerance: <0.003mm. Made of high quality specially formulated spring steel, first class 1065 carbon steel. Widely used in drilling, CNC milling tool, threading, grinding, engraving machine. Correct collet mounting methods: 1. Place the chuck into the pressure cap, gently rotate the collet spring when the eccentric part of the collet spring groove embedded in the pressure cap. In the direction of the arrow and using the same force to push the clamping spring, you can mount the pressure cap. 2. Place the collet spring and cap together on the chuck or spindle body. Insert into the clamping hole after wiping the cylindrical shank, use a wrench to tighten the pressure cap, until the tool is tight before use. Note: Avoid fixing the pressure cap with an uninstalled tool to avoid damaging the clamping spring. 3. Using a wrench, loosen the pressure cap and remove the chuck or tool, then remove the tool. In the direction of the arrow, push back the collet spring, and then replace the other collet spring as needed. Specifications: Model: ER11 Material: First-class carbon steel 1065 Clamping range: 1mm to 7mm (1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm) End of stroke tolerance: <0.003mm Total height: 18mm / 0.71inch Outer diameter (max.): 11.5mm / 0.5inch For metric shank sizes: For example, a 1mm collet fits a metric shank, a 2mm collet fits a 2mm metric shank Package includes: 1 set (7pcs) x ER11 Collet