This Kingspan Insulation fanfolded underlayment measures 4 feet wide by 48 feet long, providing 192 square feet of coverage. It arrives like new and in box, with no damage or missing components. Fanfolded design makes it easy to handle and install as a continuous thermal break under vinyl siding, over existing siding, or beneath flooring. Kingspan is a trusted name in insulation with strong R-value performance in a slim, durable panel. Lowe's item #5759784, model #100077933.