Fallkniven DC4 sharpening stone

DC4 whetstones consist of a fine diamond stone (25 micron) and a very special ceramic stone, made of synthetic sapphires.
These materials are the hardest we know of: they will sharpen any steel, even these extremely hard powder steels, and will keep their flat shape.
You don't need any lubrication for these stones but now and then you should clean them with warm water and liquid soap.
The stones might feel coarse from the start but will become smoother/better after some use. A leather pouch is included, and is handy as a strop.