Diamond Grading Plates - Twin Pack

They easily and quickly remove the first layer of the stone, in my case the SG. The Tormek grinding stone also works well on the SG, but it's slower. Press gently to avoid removing too much stone; light pressure is sufficient unless you want a thorough cleaning.

Good quality! Will work well on my SB250

Only used them once. They did what they were supposed to do. They seem like they are going to last a long time.