Soundproof foam does not wait 2-3 to . Only 5 seconds can be recovered to normal size. More convenient than other soundproof foam.acoustic panels with high -adhesive to make the easy installation without additional tape.Perfect for individuals to reduce and unwanted echoes, waves, reverb, and flutter echoes. Reduce echoes and increase musical . High-density materials Acoustic Panels Soundproof Studio Foam can install on walls or doors.No smelling, Safe for use in different areas. soundproof foam makes for -friendly, and Safety materials. Perfect for professional studios, video bloggers, home theaters, rehearsal rooms, concert , podcasting, offices, etc.size: 30 x 30 x 5cmMaterial: Polyurethanecolour: BlackPackage Contents:12 x studio foamOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.