Diamonds are a woodworker's best friend.
Sharpen planes, chisels, knives, and just about anything else with an edge using this professional grade "stone". Diamonds with a single-crystal structure are actually embedded into nickel and steel. It's double-sided so you get a fine and a coarse grit.
At 8" long, 2 5/8" wide, it's quite handy.
And, there is a non-skid pad if you work without the stand.
Made in the USA.