The Rockingham Forge Combination 400 & 1000 Grit (Coarse/Medium) whetstone in the Sharpening Kit is much harder than the traditional whetstones, so will wear a lot slower. It will sharpen knives faster and is particularly good for a lot of the ultra hard Japanese steels, SG-2, HDP-40 and ZDP-189. The sharpening kit contains: the combination whetstone, a protective storage box, flattening stone and 2 angle guides.