I purchased these in 2025 to improve the acoustics of my room, but I never used them, so I'm selling them. This product sells for around 4000 yen on Amazon. Would be suitable for DTM (Desktop Music Production), etc. Brand new, unopened. No price reduction requests, please. - - - Product Details Top Highlights ♫ Our bass trap corner studio foam is made of high-density polyurethane and absorbs low/mid-frequency sound waves, improving acoustic quality. These porous absorbers are the first line of defense when addressing common room acoustic problems. ♫ Bass traps help reduce problems in the low end of the frequency response. Common acoustic panels are excellent at absorbing mid and high frequencies. They are not very good at handling the low end. Due to their wavelength, low-frequency sounds pass through regular acoustic panels unaffected. That's why you need bass traps, which are essential for recording studios. ♫ Bass traps are easy to install at home and significantly improve the acoustic response of your room. It's impossible to overemphasize the difference even a little acoustic treatment can make. They can be used with our acoustic foam panels to create a more comfortable living or working environment without unwanted sound waves, reverb, and flutter echo. ♫ Our bass trap corner blocks are made of flame-retardant and environmentally friendly materials. They have a certain flame-retardant function. They are also safe materials, completely harmless, and pose no danger when they come into contact with the human body. ★ Our bass traps are packaged in a compressed vacuum package. After opening the package, placing the bass trap foam in a well-ventilated place for about 24 hours will restore it to its normal size. Some customers soak the foam in water, wring it out, and dry it with a hair dryer. By doing so, these bass trap acoustic foams can quickly regain their shape.