1. What are the normal sizes of sound-absorbing cotton: 1. After opening the vacuum package, place the sound-absorbing cotton in a ventilated place for 12-24 hours; 2. Or put the foam into water 1, wring it out, and then air dry or use a hair dryer to dry it. 3. The principle of sound insulation cotton is that the sound inside the sponge is repeatedly reflected back and forth, thereby achieving the effect of noise reduction and sound absorption. Sound-absorbing panels not only have effective sound-absorbing properties, but also do not cause any harm to the body. High-quality material studio foam maintains sound insulation function permanently. In terms of cleaning, just vacuum and dust occasionally. 4. High-density flame-retardant material: The sound-absorbing foam board is made of flame-retardant and environmentally friendly materials, which is safe to use. The absorption spectrum is broad, exceeding 500HZ. High-density material, 30% higher than industry standard. At the same time, it also improves sound quality: by absorbing harmful sounds, reducing fluctuations, reverberation, and vibration, making useful sounds clearer. 5. Installation: It is recommended to apply tape to the four corners of the sound-absorbing foam board and the center of the back, and then stick it to the wall. Or you can purchase spray adhesive to install the soundproofing foam based on your needs. 6. Acoustic Foam for Professional Acoustic Control All uncompressed and in perfect condition Featuring professional acoustic control, sound suppression, acoustic treatment, noise reduction, acoustic foam reduces wave, reverberation and flutter in small to medium-sized rooms. Sound-absorbing panels are suitable for use in recording studios Colour: Black Material: polyurethane Dimensions: 30 x 30 x 2.5cm Package Contents: 60 x Soundproof Foam Only the above package contents, other products are not included. Note: Light and different monitors may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowance is +/-1-3cm.