HP B3Q10-40013 ADF outer cover is the top outer cover assembly for an automatic document feeder. It is a specific replacement part for the feeder’s exterior, rather than the inner cover, which is listed separately as B3Q10-40012.
The distributor lists compatibility with Color LaserJet Pro MFP M281fdw, M377dw, M477fdn, M477fdw and M477fnw; LaserJet Enterprise MFP M430f; LaserJet Managed MFP E42540f; and LaserJet Pro MFP M426fdn and M426fdw. This part is intended for the ADF assemblies on those listed multifunction printers.