This is a A-B1D189 Sharpening Stone PN: B1D189Main Description As Following : A-B1D189 Sharpening Stone P.N: B1D189 307, 308Center Hole: 1/2"Diameter: 5"Grit: 1/4", .325", 3/8" EPMaterial: ResinoidWidth: 1/8" Crossed From: S1906 PACIFIC GRINDING WHEEL Found in Section & Models : Sunbelt - Blades > Blade Tools & Accessories, Foley GRINDER, BLADE: 307, Foley GRINDER, BLADE: 308, Sunbelt - Equipment > Grinders, Foley GRINDER, BLADE: 307, Foley GRINDER, BLADE: 308 Associated Items : New Also This is An Aftermarket Product And : High Quality Afternaket Shipped from Both US and Canada