At the same time, the cooler/freezer door is designed around a single-operational platform that sets the standard in industrial door simplicity and reliability. FasTrax FR combines the unique Thermal-Flex Sealing System and the company's R-4 InsulMax insulated curtain to achieve significant energy savings in the most demanding cooler and freezer applications. The advanced technology minimizes the potential for frost build-up and the need to address unwanted frost with heat lamps.