The 150mm 6in w6 diamond whetstones are ideal for kitchen use and for the honing of smaller workshop tools they have a large wider diamond surface for sharpening a variety of knives and edges supplied in a plastic case fitted with non skid rubber feet or wooden box the base of the plastic case may be screw mounted to a bench black extra coarse grade 220 60 micron blue coarse grade 325 45 micron red fine grade 600 25 micron green extra fine grade 1200 9 micron