EverGuard® TPO outperforms its competitors in heat-aging and UV tests-the best predictors of TPO performance. EverGuard® TPO 60-mil Membrane is the best standard TPO in accelerated aging. After accelerated heat aging at 275°F (135°C) for 105 days, EverGuard® 60-mil TPO showed no cracking-while almost every one of the competitors ' samples failed. The large welding window makes it easy to install and it is complemented by the most complete line of accessories.