Moistop PF is the solution of choice when building requirements call for a mechanically-attached flashing product that is unaffected by substrates or job site conditions. Manufactured from a multi-layer composite employing heavy-duty polypropylene woven fabric, and coated on both sides with ultraviolet-resistant polypropylene, the product resists cracking and curling - both before and after installation. Moistop PF's unique construction makes it ideal for installation over OSB or plywood, making it easy to integrate with a weather-resistive barrier. It can be used on all types of windows, including wood, vinyl and aluminum casing - as well as doors. It can installs easily with a utility knife and hammer. Moistop PF is a critical element in the complete Moisture Control System for Walls pioneered by the Fortifiber Building Systems Group®. The product is engineered to answer the need for a mechanically attached flashing material that offers a unique balance between extraordinary durability and cost-effectiveness. Moistop PF resists extreme jobsite abuse -- such as heavy wind and rain -- while effectively containing costs and protecting structure.