3M 28329 disc sander provides 1/2 hp. Always consider the length of any product when purchasing an abrasive tool or accessory. This disc sander comes in a 6.75 in length. Most of the items 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 12,000. When buying power tools or abrasive accessories pay close attention to the diameter of the tool for supported diameters of accessories and abrasives. This item has a 2 in or 3 in diameter.