4 foot x 25 foot Reflectix Foil Insulation - Reflectix aluminum and polyethylene bubble insulation has been thoroughly tested and proven to be a highly efficient energy barrier that maintains temperatures and comfort levels. Use it wherever regular insulation can be used. It cuts easily with scissors or a knife and staples quickly and easily into place. With a reflection of up to 97% of radiant heat, and with an R-value up to 14.3 (depending on application) this is a great way to help save money on energy bills. It is ideal for new construction or retrofit of existing structures and is especially effective in attics, as well as a variety of other uses. Dimensions: 4 feet x 25 feet.