The 3-1/8 in Carbon Steel Knot Wire Cup Brush offers continuous brushing action for removing rust, scale and weld splatter. The durable carbon steel wire construction is ideal for tight spaces, corners, and angle welds. The X-LOCK quick change system provides up to 5x faster cup brush 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.