APPeX® 4.5M is an APP modified bitumen sheet which incorporates the features of a tough, non-woven, polyester mat that is saturated and coated with a blend of APP (Atactic Polypropylene) polymer and high quality asphalt. The premium APP asphalt blend is formulated to provide excellent physical properties for ease of installation and long-term roof performance. It has a construction that provides an extremely durable sheet with excellent weathering properties.