So this is a great block for sanding both flat and curved surfaces, and I really recommend purchasing it if you do any wet sanding. I would purchase it again.BUT, I can't help thinking that if I knew where to buy this type of foam, I could cut at least 5 of these for $10 rather than just 1. So, rather than buying more now, I'm trying to find a foam that's similar to it from McMaster or someone. There's not a lot of engineering that went into this blockit's just foam rubberthough I do notice that this block appears to be made of 2 layers of foam (black and gray), but I'm not sure if they are different density. It appears the bottom half _may_ be slightly less dense than the top half, but not sure how required that would be.I think I've even seen a similar type of foam used for packaging some products. (Things that come in those fancy durable boxes, that are sometimes hingedlike smart phones, vaporizers, airbrushesanything they're trying to give a luxury feelsometimes come with a piece of it cut out to fit the product. Keeping my eye out! Until then, go for this, I guess!