The Carrier 317659-402 Fan Coil Filter (16.5" × 21.5" × 1") is a high-quality replacement air filter designed for Carrier fan coil units. Installed in the return air pathway, it captures airborne particles such as dust, pollen, and debris, helping maintain clean airflow through the coil and blower assembly. This filter supports efficient heat transfer, reduces strain on the fan motor,... https://www.partshnc.com/317659-402-carrier-filter-165x215x1