2 Milwaukee Premium Hubbed Depressed 1/4" Metal & Stainless Steel Grinding Wheels, with a single step Mount & Grind feature that allows you to mount the wheel without the need of an inner flange or locknut, which are easily lost and expensively replaced. These wheels also feature the industry's fastest rotating operating speed, providing the fastest and effective stock removal and therefore maximal productivity. This (A24R) Grinding Wheel is made from Brown Fused Aluminum (A), a hard and tough material with excellent high strength properties. Our Industry leading 24 Grit Size is designed for aggressive surface area removal. This hard grinding disc (R) is effective on softer metals and general grinding applications. Milwaukee's long lasting and reliable bonding materials are ideally suited for grinding ferrous materials, stainless steel (INOX) and all other metal applications. Safety Note: higher operating speeds can be an effective method of increasing productivity, but operating a grinding wheel at excessive speeds is hazardous and can lead to breakage. Please refer to your angle grinder safety instructions for further information.