EverGuard Extreme® TPO is the best performing TPO in accelerated aging. After accelerated heat aging at 275°F (135°C) for 190 days, EverGuard Extreme® TPO showed no cracking. Factory-applied polyester fleece provides additional protection to the membrane and means you won't need a slip sheet when re-covering over a variety of roofs. The fleece-back also provides enhanced puncture resistance, especially in areas more prone to hail. It increases installation efficiency 2-3 times when installing fleece-back TPO with GAF Two-Part Roofing Adhesive (compared to standard TPO adhesives).