Diameter: 5 in. Thickness: 3/4 in. thick. Arbor Size: 1 in. Grit: 80 Grit. Compatibility: Bench Top or Pedestal Grinders. Abrasive Material: Aluminum Oxide. Maximum Speed: 4,965 rpm. Fit today's most popular benchtop grinders. Designed for homeowner use to sharpen knives, cutting tools and implements. Fast cutting aluminum oxide designed for high speed tool, steel, and other non-ferrous metals. Telescopic reducer bushing included, adjustable to fit 1", 3/4", 5/8" and 1/2" shafts.