3M 20231 disc sander provides 1/2 hp. Always consider the length of any item when purchasing an abrasive tool or accessory. This disc sander comes in a 12.5 in length. Most of the products in this category have a maximum RPM. The maximum RPM is designated for both safety and as the upper limit for performance. In this case the maximum RPM is 20,000. When buying power tools or abrasive accessories pay close attention to the diameter of the tool for supported diameters of accessories and abrasives. This SKU has a 2 in or 3 in diameter.