First Step 3-in-1 Premium Underlayment. Constant air movement inhibits mold growth. Excellent moisture resistance. Reduces ambient noise. Outstanding compression resistance. For use on below, on and above grade subfloors. Sound resistant underlayment for use under all laminate and engineered hardwood. Ideal for condos and multilevel dwellings. Includes adhesive strip and 4 In. overlap film for linking multiple rolls. 40" x 30' roll. 100 sq ft/roll. 12/case.