NFRC products are tested and certified by an independent testing agency according to NFRC standards. The NFRC aims to provide information the consumer can easily compare the thermal energy efficiency of products. Like the window sticker on a new car that allows you to compare the car's mpg performance in the city and on the highway, the NFRC window label allows the consumer to compare window performance in the summer and winter. Champion Window is a member of the NFRC. For more information, visit www.nfrc.org.