DEI Boom MAT Spray on for Sound Deadening 18 Oz (2 Pack) DEI Boom Mats are constructed of a rubber-based (viscoelastic) polymer layer with an aluminum foil laminate outer facing Sound Dampening Type: Spray-On Boom Mat's strong adhesive backing is unaffected by extreme hot and cold temperatures, is corrosion resistant and can be applied to In addition to being a superior sound absorber and a solution in controlling vibration over a wide temperature range, Boom Mats are also an excellent thermal insulator NOTE: Will cover approximately 20 sq. ft.