The 3M disc pad holder 922 holds a 2 inch Scotch-Brite™ Surface Conditioning Belt Disc and has a 1/4 inch spindle that mounts to a right angle sander or collet chuck tool. A 1/16 inch layer of foam on the firm density holder helps generate professional results on flat sanding applications. Is has the Dual-Lock™ System that hooks on the holder securely hold a surface conditioning disc and provide easy disc attachment, removal, and re-attachment. This feature enables the disc to be used and re-used for the extent of the abrasive life. Discs are sold separately. Max RPM is 23,000.