Doesn't last very long

This might be okay for keeping an edge on a pocket knife, but after 1 sharpening of my 6 chisels and 1 #4 plane iron, I couldn't tell which side was which due to lost grit on the 400 side. It did good on the plane iron, but I sharpened that first. The chisels got progressively harder to get the edge I need.

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