Impact resistant shingles can withstand impacts from flying objects to a much greater extent than a common asphalt shingle. The impact resistant rating system ranks shingles’ resistance to impact into 4 levels – 1 through 4, with Class 4 as the highest rating level to impact resistance. The Atlas, the StormMaster series of asphalt shingles are rated as a Class 4 per the ASTM D2218 Test Standard and insurance companies in many parts of the US actually discount premiums when the StormMaster shingles are installed in place of regular asphalt shingles. Learn more about Atlas impact resistant shingles here.