Product is foam, but not sound proofing at all. I have dish washing sponges with more density than these. They also came rolled up and its been 48 hours and they still haven't all flattened out.
10 out of 12 pieces foam were dirty and packed to me. The material of the foams are not compact and exactly like a dish washing sponge. It didn't even soundproof someone's conversation between the wall and outside my room for my case. I had to use glue to stick it on the wall since the back of the foams do not come with adhesive surface and I had to clean wall afterwards which is a nightmare. It is a waste of money and effort. On the other hand, i think these foams would rather function better as anti shock. I personally would think the corrugated E type carton boxes soundproof better than these foams unless you could get a better acoustic panel which may be costly. The acoustic soundproof materials that work well with soundproofing tend to cost a lot or require a lot of diy work.