Two Sided Diamond Sharpening Stone

This small sharpening stone (4"long  x 1 1/4" wide) is what I've been using as my primary knife sharpener for the last 10 years. Two sided diamond stone, medium grit (600) on one side, fine grit (1800) on the other. Put one in your pocket and always be ready. It can be used dry or with water.  Every now and then I wash it with soapy water to clean it up.