The Spyderco Fine (F) and Ultra Fine (UF) stones come in a standard 1"x4" mounted to a standard aluminum blank, and will fit into any standard KME Sharpener. They can also be used as field stones, slip stones, and even slurry stones. Spyderco is known world over as a knife company, and their Fine and Ultra fine stones are a must have for any Spyderco enthusiast. The fine is rated around ANSI 1200 (~2K Japanese grit) and the ultrafine is rated at around ANSI 1500 (~4K Japanese grit). Spyderco stones can be used with water, oil or dry. Due to the nature of these stones, the finished thickness will be between 4-5mm. Please choose your desired stone from the drop down menu above.