I just bought a course/extra course DMT 8" bench stone. However, on the Extra course side there are two small holes drilled on the sharpening surface in the plastic near each end! I have never seen this before. Do you think this is a defect or is there some purpose for it? I have purchased from this line before but never an extra course and thought maybe it was for some purpose, because they are very obvious and cleanly drilled. Any ideas?
Bob