Timberline Armorshield II Impact-Resistant Shingles pass the UL 2218 Class 4 "Impact" Test. This is a test where a 2" steel ball is dropped from 20ft onto the top of a shingle simulating a 90mph hit onto the shingle. The Armorshield showed no sign of breakage in this test as compared to a typical 3 tab shingle that cracked. This extremely protects against leaks coming into the home. A Hail Resistant roof will not only make you envy of the neighborhood, but also lower your home owner's insurance. Some companies offer up to a 30% reduction on your yearly premium because they know this should be the last roof you ever have to put on your home.