4 Pieces Diamond Sharpening Stone Fifchall Honing Stone Diamond Stone Lapping Plate Fine Coarse Bench Stone for Kitchen Sharpening Blade Blunt Chisel, 400, 600, 1000, 1200 Grit, with Angle Guide

Pros: Very substantial, Nice grit range, works very well with little dragging, sharpens well with practice.Cons: NoneBest Use: Sharpen knives, scissors, and other cutting utensils, Throwing at the neighbors cat.Observations: Since there is no rolling guide or swing arm to guide the sharpener you have to develop the right touch to maintain the correct angle for the utensil you are sharpening. These work best with either some light mineral oil or water on them to prevent blade drag and hop. I was able to resharpen used 4" scrape blades that were one time use. It made them several time use blades. Excellent value.

Nice product

These work well as garden tool sharpeners. Hold them at an acute angle as you drag them across the blade surface. The softer metal shaves away to leave a bright edge.

Great for sharpening my carving tools

They are not the largest size. Check the dimensions if you are looking for a specific size. But size was as advertised. A good size to use in your hand if sharpening something oddly shaped or at an angle. I was looking for an inexpensive set. Used a couple of times so far and they do the job. So far I would recommend.

Takes a while to get a fine edge, but goes the length of the blade

I’ve been using these to keep my router bits sharp. They have worked great. They’ve lasted through 10 sharpening. Still just like new.

While I did not expect the metal plates to be flat to a high degree (given price and thickness of base metal), I did expect not to have visible curve over the short axis. Due to the purpose of purchase (why I actually needed them to be thin) the curve isn't an issue but is my reason for such a low rating (expect at least visually flat). I have not used them enough to judge durability although the edges I did use are significantly less rough than the rest of the body (unsure if original is correct or current after being used lightly). With thickness, having the foam bottoms are nice for laying out and stacking on-top of each-other.Dimensions: ~5.97" x 2.49" x 0.05" (need calipers or better eye-sight for closer estimate)Short axis concavity mostly is in middle although one is ~1/4 from the edge with depth of 0.01-0.02" from edges using just rulers (don't have any of my feeler gauges on me) without the main faces being used to knock down surface finish (grit).Long axis more complex with both concave and convex shape (although appears to be with the same tolerance without checking).