MSI showed off its interesting M.2 XPANDER-AERO SLIDER at Computex 2024 earlier this month, and while it might look like a graphics card... it's not: it's an expansion card that houses not one, but two M.2 PCIe Gen5 SSDs which is impressive.

MSI's new M.2 EXPANDER AERO SLIDER GEN5 (source: 3DNews, Windows Central)
The new MSI M.2 XPANDER-AERO SLIDER can hold two M.2 22100 form factor Gen5 SSDs, as well as supporting hot swapping, which means you can remove either of the Gen5 SSDs at any time (if that's something you need, or want to do).
MSI is providing some active cooling with its AERO fan cooling system for the Gen5 SSDs, with two cooling modes on offer: the fans can stop completely if the SSDs aren't running hot enough to require active cooling, or an automatic mode when the M.2 SSDs are removed.
MSI supports an EZ-slide design for effortless M.2 installation and upgrades, the AERO fan design as an exclusive thermal solution to keep your Gen5 SSDs cool and at maximum speeds. There's a single 6-pin PCIe power connector, but as VideoCardz points out, the PCIe slot itself has enough power to support dual Gen5 SSDs... yet there's still a 6-pin PCIe power connector on the M.2 XPANDER-AERO SLIDER.

MSI's new M.2 EXPANDER AERO SLIDER GEN5 (source: 3DNews, Windows Central)
MSI also has the M.2 XPANDER-Z GEN5 expansion card which is a completely different beast to the M.2 XPANDER-AERO SLIDER, which is an adapter that MSI supplies with its MEG AMD X670E motherboards. The M.2 XPANDER-Z GEN5 also expands support with an additional two M.2 interfaces, but at the cost of one PCIe Gen5 interface. Another difference, is that the XPANDER-Z GEN5 is a tight single-slot design.
MSI has said that its new M.2 XPANDER-AERO SLIDER is coming in the next few months, but we could also expect to see the company launch it as a Gen5 SSD accessory for new X870E motherboards from AMD, and new Z890 motherboards from Intel in the coming months.