PCI slot cover 3 DisplayPort and 1 HDMI w/ cover box
Another version of https://www.thingiverse.com/thing:7046422- this version includes a cover/cap to hide the bulkhead cable connectors. The cap is held in place with #4-40 socket cap screws - supply your own. The cap has tapped holes for the 4-40 screws - the bulkhead cable connectors use through holes because the slot cover is too thin to support a chamfer for a recessed screw head. From the original:
Dual-width PCI/PCIe slot cover with cutouts to accommodate 3 DisplayPort and 1 HDMI extension cables. Designed with vertical GPU mounts in mind where the ports on the video card are no longer externally exposed. 3 DP and 1 HDMI were chosen based on my 50-series Nvidia GPU. NOTE: this design is not universally compatible with all extension cables. For proper fit, use the following:
L-com DP20P-MFP-BLK-xM, where x = 05, 1, 2 and indicates cable length of 0.5m, 1m, or 2m, respectively. This is a DisplayPort 2.0-rated part (forward-compatible with DisplayPort 2.1).
L-com HD21P-MFP-BLK-xM, where x = 05, 1, 2, 3 and indicates cable length of 0.5m, 1m, 2m, or 3m, respectively. This is an HDMI 2.1-rated part.
Screw holes are sized for 4-40 bolts. They're clearance holes, not threaded, so you'll need nuts to secure them.
Edit: updated to v2 with increased thickness of the PCI slot cover (1mm changed to 2mm) and 5mm additional cap height to allow a larger bending radius for the extension cables.