3.1 is one of the most advanced sound dampening materials on the market. It uses 3mm of a specially formulated butyl rubber and polymer composite reinforced with 100 microns of aluminum to offer a sound dampening material that’s twice as thick but just as light as most leading brands offerings while also outperforming the thicker and much heavier materials of lesser quality. This means easier installation and better attenuation of unwanted energy such as road noise, vibration, panel resonances, and sound bleed from other cars playing non-DD sound systems. EA-3.1 comes in a bulk roll with one pack covering over 40sq feet. One roll is generally enough to do a single layer application in most standard size cars or more than one layer in sub-standard size cars.