Glasswool is a sound-absorbing material made from glass fiber. The main function of glasswool is to reduce sound intensity from the resonance of the panel that reaches the ear (soundproofing) and its supporting function is to retain heat. Sound-absorbing materials are generally soft and porous materials, such as foam and the like. Because, apart from being very effective at reducing sound intensity, the material is also elastic. Harijaya Insulation Surabaya Sells Glasswool which is known as an excellent insulation material or heat and sound absorber. This product is easy to use and elastic, so it is easy to install and can be adjusted according to needs.