Brothers Trucks UCSP003 Chevrolet & GMC Sound Dampening Kit

This is the insulation found on the floorboards under the carpet, it is a thin "tar-like" material that was installed at the factory and was designed to absorb sonic resonance in the floorboards. It is also used for absorbing moisture that can eventually cause rust. This is for a large hump. Large hump transmission tunnels have a removable panel bolted to the floor.