Fallkniven Cubic Boron Nitride sharpening plate. Dimensions: 85mm x 54mm x 3.6mm. Cubic boron nitride is an extremely hard synthetic crystalline material. CBN is superior in terms of resistance to abrasion and oxidation in contact with steel alloys. It is particularly suited to stainless steel knives and hardened stainless steel cutting tools. CBN is no harder than diamond, but is thermally and chemically more stable than pure diamond. Another feature of the CBN sharpener is that it retains its shape regardless of use. What's more, this coating is located on both sides of the profiled stone. 25-micron grit size on both sides. Lanyard hole.