Lyndex line of high-quality ER Collet Chuck offers more rigidity and better accuracy than the competition. Ball bearing nut with ground collet race. Ground surface for perpendicular contact between retention knob and holder. AT3 or better taper. Equipped with a left-hand-threaded stop screw. Available in high-speed balanceable versions. Set-up: quick and easy. Speed: up to 23,000 rpm. Tolerance: less than 0.0001 at collet face. Ideal for drilling, milling, reaming and tapping.