Trend FTS/S/R Roughing Stone for Fast Track Sharpener Roughing stone for the Fasttrack sharpening system. FEATURES Monycrystalline diamond with unique Diamond Cross relief pattern which gives optimal abrasion rates to maximise sharpening efficiency and reduces clogging Diamonds are held by Nickel plating to a steel substrate, with ABS plastic base SPECIFICATION Size: 75 mm x 24 mm x 4 mm Grade: Extra Extra Coarse Grit: 90-120 (nom. 120 micron) Colour: Silver