Insulating Foil - Suppresses noice, heat, cold and moisture that can interfere with the comfort and quiet of your motorhome. An excellent lightweight easy to install insulation for Genset compartments, engine covers/compartments and under carpet or floor mats (does not affect fit of any component that is installed under). 3/8 thickness is made up of a dense packing of recycled cloth material, a highly effective "Firex" fire retardant coating and a space age aluminized outer layer. Trim to any shape with household scissors and adhere in place with "Sticky Stuff" spray adhesive (#49897). Seal edges with "insul-tape" (#40592). Conforms to FMVSS safety standard 302. Coast Guard F.A.A. approved (aircraft grade only). Install with foil side toward source of heat or noise. 1-Sided.