STOREFRONT IS IMPACT RESISTANT The Series 526 Thermal Impact Storefront from EFCO accommodates 1 5/16-inch (33-mm) insulating glass units for enhanced U-values and impact resistance. The product incorporates a polyurethane thermal barrier, and dry-glazed interior and exterior gaskets eliminate the use of silicone sealants. Screw-spline frame construction decreases shop labor. (800) 221-4169 /