ROBERTS AirGuard Premium Underlayment is ideal for use under floating laminate and engineered wood flooring. It features an innovative AirFlow Technology that releases trapped moisture as a vapor to prevent damage to floors and subfloors. Its 3-layer design protects floating laminate and engineered hardwood flooring: The top layer is made of an impermeable film that keeps moisture away from flooring; the middle layer consists of thousands of cushioning, stabilizing polyshims that support the finished flooring; and the bottom layer is a permeable film that wicks moisture up from concrete or wood subfloors. ROBERTS AirGuard is the first underlayment to include MICROBAN antimicrobial protection to safeguard the floors against moisture, mold, mildew and odor-causing bacteria. Recommended for residential and commercial applications, AirGuard is made in the USA. Material: Plastic.