The GeneralAire 4757 is the correct replacement power box lid for the following air cleaner models:
The GeneralAire D1-0509 Power Box Lid is a replacement power box lid for the GeneralAire GA50A20 Electronic Air Cleaner. The D1-0509 power box lid covers the D8-0501 power box, which encloses many of the crucial internal electronic components of your High Efficiency Model GA50A20 Air Cleaner. The GeneralAire 4757 is manufactured from durable construction material that is built to last.
GeneralAire D1-0509 Power Box Lid specifications: