3M CP000-6P-CC Extra Fine Grit, Black, 3-3/4 in x 2-5/8 in

Not ok

These appear to be made of a rough exterior material (as opposed to gluing sand to a sponge) so they don't leave behind grains of grit. Last long and make sanding much easier that a hard block (which too often cuts all the way through the paint to show the primer or base material).

I use this for cleaning. You can scrape off the limestone residue from hard water by scrabbling with this sponge. It works well. But as you use, it gradually wear off. So you will need multiple.

This worked really well when used to sand between coats and spackling. I am very pleased with this purchase and the number you get with it. If I were to be constructively critical, I might suggest they make one of the edges angled to assist with the occasional challenging spot. Also, because you get a box full, numbering each unit so that you can keep track of them and not just keep going back to the box because you know you have a ton, would save time and waste (if especially if you’re working around other contractors who might have similar-looking units lying around).

When I received this product my first impression is that it's coarse, which is deceiving, because after using it on several projects, it truly is extra fine grit and I am definitely sold on this awesome product. I have purchased these a couple of times already and I will continue to order more in the future. It is a great product.