This is sound-absorbing material for car deadening, called "Magic Insulation Jacket." It's best used in conjunction with deadening sheets (vibration damping sheets). This big size pack contains 10 sheets, and is on special offer for 12,980 yen, down from the usual price of 19,900 yen! That's a saving of 6,900 yen or more! 【The Latest Buzzworthy Sound-Absorbing Material, Here's What Makes It Great!!】 ・Material Focused! By using plenty of PP (polypropylene) and PT (polyester) materials and layering them, it exhibits higher effectiveness than general felt materials! ・Installing it inside the doors will allow you to feel better sound quality. You'll notice a difference not only with music, but also with the sound from your TV! ・Due to its heat insulation and heat retention effects, your air conditioner will work better, keeping you cool in the summer and warm in the winter! ・In fact, it's made of the same material used in Shinkansen (bullet trains)! We wanted to deliver a higher quality product, as it's something you can use forever once installed. 【3 Effects in 1 Sheet!】 Insulation: PP material has excellent insulation properties and works effectively without being affected by humidity. Heat Retention: Reflects external heat. The thermal conductivity is as low as s0.030W/mk, maintaining a comfortable temperature with less energy. Sound Absorption: Eliminates phase shift by suppressing sound reflections (improves the sound quality of sound systems). 【Size】Approximately 80cm x approximately 50cm Quantity: 10 large sheets If you need a different quantity, please inquire in the comments section. Shop Kaze Kobo also offers many other products, such as headlights, fog lights, and sound quality improvement sheets, so please check out the hashtags and my page! #shopKazeKoboSoundQualityCommittee 【Product Description】 Material: Material made by layering polyester and polypropylene Heat Resistance: Non-flammable Usage: The back is fully adhesive, so you can easily cut it to your desired shape. 【Impressions】 This is my personal experience using it. Regarding sound quality, it has improved dramatically. There is no echo, and the sound is directly transmitted to the ears, making it pleasant to listen to. I was impressed, thinking, "So this is the original sound of the speakers." Recommended for those who are using Regetrex, Real Schild, and other deadening vibration damping sheets, vibration isolation materials, and damping materials. We support those who are challenging deadening with DIY!