GATCO Sharpening Hone Grit:Extra Coarse If you do your measuring

If you do your measuring in inches

1/4"" thickness

Attaches to the roller assembly of the MK II Honing Guide

And lastly

Both the mounting and file slide castings are larger in size for heavy use

GATCO Sharpening Hone Grit:Extra Coarse If you do your measuringThese GATCO Sharpening Hones are a direct replacement for your GATCO Knife Sharpening Systems. Whether you need to add to your set or replace an old stone, these stones are perfectly matched for any of the GATCO Systems using the Knife Clamp Guide System. Please select your Grit. Extra Coarse: Black Color, 80 Grit, Sharpens damaged edges and extremely dull blades. Coarse: Yellow Color, 120 Grit, Fast cutting, resharpens dull blades Medium: Green