Atoma Diamond Plate #140
They are also great for repairs as they can very quickly remove steel from a knife. We wouldn't make a habit of using it to sharpen knives though as doing so will pull diamonds off the surface making it less and less effective as a flattening or sharpening tool. Should you wear out your diamond plate, you can peel off the diamond pad and replace it down the road when that time comes.
#140 is quite coarse and will leave DEEP scratches when thinning, it is not recommended to thin a knife unless you have an adequate progression of stones to work out those scratches.
It is sometimes stated that the #140 will leave the surface of your stone too rough, though unless working on razors, we've not noticed it to be an issue, nothing a quick kiss with a nagura won't fix if you are though!