The Same Architectural Selection Of Cambridge Shingles PLUS Class 4 Impact Resistance Rating Technology (to help protect your home against hail). Enjoy similar designs and color schemes to IKOs flagship shingle, the Cambridge, as well as the same easy-to-install technology. When you live in a part of the world that gets more challenging weather, Cambridge IR Shingles give you best-fit technology and the confidence of a roof capable of protecting your home. Cambridge IR has elite impact resistance technology (UL2218 Class 4 Impact Resistance Rating) so youll be more protected against the weight of heavy snowfall, and the damage hail can cause. With the contemporary looks of Architectural Shingles, Cambridge IR Shingles are made to match any style of home.