This versatile sharpening block has 4 sides with 4 different grades of diamond for honing and sharpening blades of all types. Red side (fine) Green side (medium) Yellow side (coarse) Blue side (extra coarse) Size of each side: 150mm x 50mm. Can be used wet or dry. Also come with a block holding case that has non-slip rubberised feet at either end for ease of use.