Original Knife & Tool Sharpener assorted replacement belt kit includes (2) P80 coarse grit abrasive belts, (2) P220 medium grit abrasive belts, and (2) 6000 fine grit abrasive belts. These abrasive belts are direct replacements for the abrasive belts that comes standard with the Original Knife & Tool Sharpener. Size: A 1/2" x 12" Grits: P80 (201 microns)*; P220 (68 microns)*; 6000 (4 microns)* Abrasives: aluminum oxide (P80); ceramic oxide (P220); silicon carbide (6000) Backing: waterproof polyester (P80, P220); flexible cotton backing with polymer emulsion cushioning layer (6000) Manufacturers: Norton (P80 & P220); Micro-Mesh(TM) (6000) Colors: Green (P80); Red (P220); Grey (6000) *There are many naming conventions for grit measurement. We include the size of the grit in microns as a standard for comparison between abrasives (higher numbers = more coarse). Many other factors contribute to an abrasive&';s application and material removing properties, including the shape of the grit, the pattern the grit is applied to the backing material, various characteristics of proprietary abrasive materials used by different manufacturers, etc.