When both an Output Expander and High Capacity Output Expander are installed, the Output Expander must be installed above the High Capacity Output Expander.Up to 3 Output Expanders may be supported at a time. Any combination of Output Expander and 4-Bin Mailbox for up to a total of 3 devices may be configured.This unit supports up to 500 sheets of paper (20 lb., 75 gsm). Envelopes, transparencies, card stock and labels are also supported with this unit.The Output Expander supports bin 'full' sensing.