Owens Corning TruDefinition® Duration FLEX® have been testing by both UL 2218 and FM 4473 standards. This rigorous testing has proven the effectiveness of this product to withstand larger hail, resulting in significant reductions to homeowners insurance premiums! Under the shingle, we used Titanium® PSU30 Hi-Temp ice & water barrier accompanied by DeckDefense® High-Performance underlayment installed with premium capped ring shank nails. We use the highest installation practices and exceed the minimum code standards in virtually every aspect of the project!