EverGuard Extreme® TPO UN-55 Detailing Membrane provides roofing contractors with an easy-to-install factory-built detail. EverGuard Extreme® TPO UN-55 Detailing Membrane is constructed using GAF's proven, durable, high-performance EverGuard Extreme® TPO. This accessory is used as an alternative material for flashing penetrations and corners of base and curb flashing.