Apple Video System - Manual (Page 17)

10 Making sure the grounding clip is on the card (as shown
in step 9), plug the video input card firmly into the video-in
slot on the logic board. Fit the three ports on the card into
the port access hole. Make sure the card is firmly seated in
the slot.
Video-in slot
Ports
Vertical plate
Port access hole
Check to make sure the grounding clip is
attached to the card before installing
the card in the video-in slot.
11 Installing the Card and Software and Connecting Video Equipment