The 1x4 KME Spyderco stone kit comes with - Medium, Fine, and Ultra Fine (UF) and will fit into the standard KME Sharpener stone holder.
Stones are 1"x 4" x 4-5mm thick and are mounted to a 2mm thick aluminium blank. They can be used in the KME sharpener, or as field stones, travel stones and slip stones.
The Medium Spyderco stone is an excellent transition and clean-up stone from the KME diamond and great for maintenance sharpening. Its about 1200 grit / 15 Micron.
The Fine Spyderco stone is also a very effective transition and maintenance stone, leaving a very respectable working edge. It's about 2K Grit / 6 Micron.
The Ultra Fine (UF) Spyderco stone is a must have finisher stone, and is rated at about 4K grit / 3 Micron.
Spyderco stones can be used wet with oil or water, as well as used dry. Wet use will gives the stones more aggression while dry sharpening will produce a finer finish over time.