A. This roller is a tool for the installation of automotive sound insulation and shock-absorbing sheets, specifically designed for automotive sound insulation installation. Its excellent design can greatly improve the efficiency and effectiveness of the installation. B. It comes in various specifications, namely 7mm, 21mm, and 42mm. These different specifications can meet a variety of installation needs. Regardless of the size of the installation site or the fineness of the components, it can be precisely adapted. C. During the automotive sound insulation installation process, this roller plays an important role. It can effectively compact the sound insulation and shock-absorbing sheets, ensuring that they fit tightly with the corresponding parts of the vehicle, thus avoiding gaps or hollow areas. As a result, the sound insulation effect will be significantly improved, creating a quiet and comfortable in-vehicle environment. D. Whether you are a professional automotive sound insulation installer or an enthusiast with the idea of doing automotive sound insulation installation by yourself, this roller is a practical tool.