Roberts Black Jack is engineered as a superior grade 2-in-1 underlayment for laminate and engineered wood flooring. It is ideal for use with many types of subflooring. The 2.5 mm thick foam layer provides optimal cushioning and sound absorption. The closed cell foam design provides excellent moisture, mold and mildew resistance. Includes a 4 in. overlap and adhesive strip to seal out moisture and join multiple rolls.