Professional Studio Soundproofing Solution Why Choose Donner? First, we strictly adhere to the optimal ratio of raw materials to produce each piece of Donner acoustic foam. Some sellers substitute a key component with cheap stone powder, reducing costs but compromising quality. While visually similar, this inferior acoustic foam fails flame retardancy tests conducted by SGS. Donner acoustic foam passes the SGS test. Second, we've tested our acoustic foam at Tsinghua University's Building Environment Testing Center. The NRC (Noise Reduction Coefficient) is 0.8, an excellent result; an NRC of 0.8 or higher signifies A-class noise reduction. Donner Acoustic Foam Panels - Quality Kit In a recording studio, hard wall surfaces cause unwanted sound reflections, and corners create echoes, resulting in unclear sound. Donner acoustic foam panels effectively solve these issues. Donner's sound-dampening foam uses a new polyurethane sound-absorbing material, processed through a mature foaming process, significantly improving your room's sound quality. Note the difference between sound absorption and sound insulation. Package Includes: 12 x Donner Acoustic Foam Panels Usage Notes: Upon opening, the foam may appear thinner than expected. Soak in water for 5-10 seconds, then air dry to restore its normal thickness. Note: Adhesive stickers and acoustic foam spray adhesive are not included. Installation: You can use adhesive stickers or acoustic foam spray adhesive. For stickers, ensure the wall is smooth and clean. For rough walls, use spray adhesive. Clean the wall first. Using Stickers: Attach stickers to the foam panels before applying to the wall. Attaching directly to the wall may cause the foam to fall. Use 5 stickers per panel. Using Spray Adhesive: Spray evenly onto the panels and attach to a clean wall. Direct application may damage the wall upon removal. For large areas, attach panels to a board first, then attach the board to the wall.