Arrowzoom 20 Pack Soundproof Door Kit Pro Panels – Self-Adhesive High-Density Foam Tiles, 12"x12"x0.78", 40dB Noise Reduction Acoustic Sound Insulation for Interior Doors & Home Studios – White 1244

Great adhesive. Stack well together and look good. Not easy to cut pieces neatly for smaller spaces.

This does not work, does not do what it is meant for. The installation is easy but when they ask you to return it, it is impossible to get it unglued. Sound goes through it like if nothing was there.

Missing one panel and didn’t catch the missing piece until mostly installed.

$200 for this?? I've tried various soundproofing products. The most important factors are a very high density, rubber or foam material that will absorb the sound. They need to have some physical weight and thickness to them. What I received as this product was a dozen really thin, super light pieces of foam. I was disappointed the second I picked up the box which weighed almost nothing. A complete waste of time. Not worth $20 much less $200. I'll keep researching for a better option.