6mm x 4 x 8 in. Integraply Underlay is a high-quality underlayment solution designed for a variety of flooring applications. This product features a uniform light rotary cut face and a hardwood back, providing a voidless solid core with no defects or repairs on the face. The underlay is fully repaired and sanded on the hardwood back, ensuring a smooth, even surface. With a BB/CC grade and sanded on both sides to uniform thickness, this underlay is i for achieving a finish. Integraply Underlay is engineered for ease of use, scoring and snapping easily with a knife. The product is CARB-2 compliant with low formaldehyde emissions and exterior glue, ensuring safety and environmental responsibility. All sheet faces are stamped with "Xs" uniformly every 4 inches, adding no thickness to the markings. It is dimensionally square within 3/16″ as to length/width, adhering to HPVA standards, and maintains a moisture content of 10–12% by weight. This underlay is backed by a lifetime limited warranty and has been tested and by leading brands such as Armstrong, Mannington, and Tarkett. It has also been classified as "Extra Heavy" use for floor and wall ceramic tile by The Tile Council of North America, making it a reliable choice for both residential and commercial applications. Model Number: INTEGRAPLY