New in sealed box. The Wolf 818337 BLOWER WHEEL is designed for use with a 600 model in the EXT series, specifically for service applications. As a heat shield or heat plate type of product, it is likely intended to enhance the efficiency and performance of the heating system. The Wolf brand is known for producing high-quality heating and cooling parts and accessories, making this blower wheel a reliable option for maintaining or repairing your HVAC system.