Coghlans says about the Sharpening Stone
Compact whistling kettle for ""on the go"". A blunt knife, a blunt pair of scissors or a blunt axe; all of these can be sharpened with this whetstone. Ideal when camping, hiking, backpacking or on the boat. Using the coarse or fine side, all knives or tools will be sharp and functional again. This pocket-sized whetstone comes in a pouch.