3M Connectors PCIe Express Extender Assemblies
This PCIe to PCI Adapter Card lets you use low profile PCI expansion cards in a server or desktop motherboard PCI Express slot. Compliant with PCI Express ...
PC/104 - Wikipedia
Under the general terms, PCI Express is used for the representation of the expansion slots on the motherboard of your computing device – whether PC or Laptop.
VACON® Functional extensions
General Motherboard Information (model, chipset, slots, PCI Express and USB supported versions).
What are PCI Express 4x slots made for? | Tom's Hardware Forum
I have a PCI Express 4x slot on my Asus Crosshair motherboard. It is open ended, but there are capacitors directly behind it blocking any 16x cards. So, what are PCI Express 4x slots for? What would I put there?