Keeps your water stones flat. As you use your stones, they tend to wear more in the center, which needs to be corrected to keep your stones sharpening evenly. It has five diagonal grooves molded into its surface to allow for waste particles to be removed.
#220 grit Flattening Stone Dimensions 170 x 55 x 30 mm
Made in Japan
Designed to be used on the ceramic Naniwa Super Stones.