Features and Benefits:Tool hones drum brake wheel cylinders and disc brake calipers from 1/2" to 2-1/2" and 12mm to 50mm in diameter;Sleeve makes insertion in cylinder easy and protects stones when not in use;Use with a variable-speed drill;Use 2004D stone set for disc brake honing and 266 for drum brake honing;Since our beginning, GEARWRENCH automotive specialty tools have been driven by innovation. From our first specialty tool, the Model-T valve spring lifter, to our latest ratcheting puller, we�ve built our reputation with tools that make tough jobs easy. Most of our products have been upgraded with new improved features like dual material handles designed for a more comfortable grip or dual dipped handles on pliers providing more cushion for your hands. GEARWRENCH automotive specialty tools are proudly made with the finest components under the most stringent manufacturing guidelines. Made for everyday use ‐ guaranteed for life. Better tools mean easier, more efficient work so we constantly evaluate automotive engineering trends allowing us to consistently improve and enhance our tools to better fit professional hands. That�s why they are the first choice for thousands of automotive technicians worldwide.