DC Series Size AxB IP Rating Max Airflow Features SDK1238EAN (HR) Dia.108x41mm/4.3inch 125~60CFM SDK1238 (HR) Dia.108x36mm/4.3inch 105~65CFM SDK1225 (HR) Dia.113x29mm/4.45inch 86~45CFM SDK9225 (HR) Dia.86x26mm/3.3inch 66~25CFM SDK8025 (HR) Dia.72x25mm/2.8inch 48~22CFM SDK6025 (HR) Dia.56x25mm/2.2inch 38~12CFM