Coarse is blue, 45 micron/ 325 meshFAST: Hardest material, most efficient sharpening abrasive; available in unique interrupted surface and continuous surface
The Dia-Sharp® 4" Continuous Diamond Sharpening Stone delivers full-size sharpening while maximizing work and storage space. Perfectly suited for small contact area and pointed tools, and available in Coarse, Fine and Extra-Fine diamond. Diamond grade clearly marked on side of stone; size = 4" x 7/8" x 3/16". C-Coarse (Blue 45 micron/ 325 mesh); F-Fine (Red 25 micron / 600 mesh); E-Extra-Fine (Green 9 micron / 1200 mesh).
EASY: Light pressure produces a sharp edge with just a few strokes
CLEAN: Use water for lubrication- no oil, smell or mess
VERSATILE: Hones ALL hard materials: carbide, steel, etc
DURABLE: Starts flat, stays flat - provides years of consistent, reliable use
Made in USA See 'Ships Direct from Manufacturer's link for warranty and return details.