Usage Tips:[Save Your Money] acoustic foam comes with self-adhesive, tear off the double-sided tape on the back and attach it easily. No need to buy additional double-sided tape. At the same time, we also provided some additional double-sided tapes for free in case of any special situation. [Save Your Time] sound panels are made from high density polymer rebound material that will expand to the old shape within second. [Thicker Make it Better] Compared to other 1 inch sound dampening panels, 2 inch pyramid 3D acoustic design add modest soundproofing to reduce outside noises. Best for home or studios to help reduce reverb, flutter echo, and unwanted reflections. [Eco-friendly and Safety] Made up of fire-retardant material, making it safe for any location in the home or studio. There may be a slight temporary smell when opened, which is normal and harmless and will go away soon. with adhesive backing, the color is random, no designation is accepted Colour:Black Material:Polyurethane Size:About: 30x30x5cm Package Contents: 24 x Soundproof Wall Panels Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.