Sharp Dual Automatic Document Feeder. Easy to install. 

MX-4140N/MX-5140N: Up to 100 sheets can be inserted.
MX-4141N/MX-5141N: Up to 150 sheets can be inserted

https://business.sharpusa.com/portals/0/downloads/Manuals/MX-4140N-4141N-5140N-5141N/contents/01-030.htm