NVX Car Sound Deadening [12 sq feet] 4-sheet Door Kit [SDDK12] Eliminates road noise that increases sound quality and output of car sound system Up to 30% thicker than the other brands providing best dampening kit value With 12 square feet of easy-to-form aluminum material, enough to cover all problem areas bothering you for so long Significantly reduces rattle and vibrations from heavy bass Made from 100% Butyl Rubber that stays in place even when its hot, easier to cut and install