Boom Mat Speaker Performance Kit solves the problem of vibrations and annoying rattles caused by speakers. Boom Mat Speaker Performance Kit is the perfect solution for quickly improving speaker sound and performance by reducing vibrations and improving acoustics. Kit includes 4 sheets of 6in x 12.5in (2.1 sq. ft.) Boom Mat Damping Material. Simply remove the speaker, apply Boom Mat on metal mounting surface and re-install speaker. It's that simple! Product Features:Eliminate squeaks, rattles & improve acousticsFlexible - can be applied to irregular surfacesUnaffected by temperature extremesWorks great on steel & fiberglass or plasticEasily trim to size, peel & stickKit includes: 4 - 6 x 12.5 (2.1 sq ft) sheets of Boom Mat Damping Material