Product selection of materials, high-quality spring steel! long lasting Clamping force, wide clamping range, high accuracy Wide range of applications, for example, boring, milling, drilling, tapping, engraving, CNC, and other processing. Suitable For: Boring, milling, drilling, tapping, engraving, CNC, spindle machines, and other processing Specifications Material: Spring steel Color: silver gray Size 1/8:0.3cm 1/4:0.6cm 1/2:1.2cm How to use Insert the tip into the pressure cap, gently turn the retainer until the pressure cap eccentric retainer portion recessed groove along the direction of the arrow evenly push hard retainer, you can mount the internal pressure cap. The pressure cap with retainer mounted together on a spindle or chuck body, the cylindrical tool shank after wiping loaded clamping hole, use a wrench to tighten the pressure cap even force until the date before the tool folder in prison use. (Note: not in the tool and avoid tightening pressure cap installed to avoid damage to the retainer) ATC with a wrench loosen pressure cap out of the chuck and the tool, remove the tool, retainer direction of the arrow push hard to quit, and then need to put on retainer to the other aperture. Package Contents: 3 x ER20 Spring Collet Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.