Foredom Abrasive Cleaning Block, Style A-AC1. 3" x 3" x 1 1/2", Abrasive Cleaner is like a giant eraser - it feels like an old shoe with a neoprene sole. It restores clogged areas and voids in abrasive stones, typhoons, flex diamond, sanding bands, discs cartridge rolls and other abrasives. Run at low speed and hold accessory against the block to remove embedded grinding debris. Use even after cleaning with diamond hones.