This is a height adjustable mount I made to stack monitors on top of a Dell U3011. This adapter slips on the stand of the Dell U3011. On top I use a Dell 2412MB from which I used the Vesa mount plate to attach it to the stand. I also included a 100x100mm Vesa mount adapter for other monitors. I have this U3011 for a few years so the mount on newer Dell monitors has likely changed and would need a different bottom adapter to fit securely. I printed this in Carbon fiber PETG. 2x 3/8-16 1.5-2 inch internal hex screws. 2x 8mm M4 2x 12mm M4 6x 16mm M4 1x 50mm M4 Hex head 1x 60mm M6 hex head, washers and nut (4x 20mm M4 for VESA mount)