AR780 F3 has two hot-swapped expansion slots which can support LAN card, storage card, etc. Follow these instructions to install expansion cards.
1. Press the tab to pull out the hot-swapped PCIE riser bracket.
2. Release the screw on the PCIE dummy bracket and open the iron bar to remove the PCIE cover shield.
3.Insert the PCI-E card in the direction of arrows as shown.