The X-LOCK 4-1/2" 40 Grip Type 29 Angled Flap Disc is designed to work with angle grinders for fast material removal in blending, deburring, grinding, polishing of stainless steel and metal applications. The zirconium abrasive grain runs cooler and lasts longer than aluminum oxide. These wheels work on a variety of materials including brick, stone and masonry. The X-LOCK quick change system provides up to 5x faster wheel changes vs. a standard angle grinder mount. Simply pull the release lever on the X-LOCK Angle Grinder and change the wire cup brush- no tools needed. These wheels are designed to be used with Makita X-LOCK Angle Grinders (XAG25, XAG26, and GA4570 - sold separately) or any angle grinder with a 7/8" arbor.