Compact, lightweight diamond whetstone for sharpening knives quickly. It has two slots sharpening, which correspond to the optimal profile of the cutting edge - an edge for the initial removal, the other for polishing.
To sharpen a knife  drag your blade through the coarse side then drag through the fine side to get a sharp edge.

Specifications:
Length: 7 cm
Weight: 17 g
Manufacturer: Gerber, USA