Soundsulate Fiberglass Backed Mass Loaded Vinyl is a multi-purpose composite material featuring a flexible barrier laminated to an insulating and acoustical quilted fiberglass and finished with protective layer of Foil Scrim Kraft. This combination forms a thin acoustical product that provides superior sound transmission loss. Sound waves originating from the source will be initially absorbed by the fiberglass and then blocked by the mass loaded vinyl. Any reflected sound wave components will be dissipated into the fiberglass absorber. The addition of the foil scrim kraft outer layer provides a vapor-barrier and fire rated product.