Focal B.A.M XXXL Sound Insulation KitB. A. M XXXL Soundproof up to four doors This soundproofing kit comes in rolls of 0. 5 x 6 m, i. e. three square meters. The B. A. M. is indispensable for soundproofing your vehicle. Once installed, the bass level of your audio system increases surprisingly, and external noise doesn't interfere with your listening. Use this kit to soundproof up to four doors or any other strategic parts exposed to these vibrations (roof, trunk, etc.). HIGH PERFORMANCE