Bought a Nuc9 Pro with a Xeon for a Server and needed a second server that was a Xeon with ECC.  Found this card available.  Thanks to der8baur on YouTube-which has a guide to tape the PCI-e pins- search Intel said couldn't be done Nuc 9.  I taped mine to x2 by holding up an x2 card next to the compute element and tape accordingly.  There is a pic-e to cpu power cable available https://www.amazon.com/dp/B08M5F7K5J?psc=1&ref=ppx_yo2ov_dt_b_product_details. which is needed to adapt the nuclear 9 pic-e power to cpu power and is plug and play.  The installation was simple.  Remove the side crossbar.  Insert the second compute unit and plug the cpu power cable.  On my project. I cut both pic-e slot rear bars on the case to plug in a monitor. Limitations- the second card is 100% dependent on the power status of the primary card.  If you are going to be 24/7 on as a Server, you are good.  If you want to reboot one, you select shutdown the second card and then shutdown on the first.  Then restart by front power button and have both set to start at power up.  There is also a power button on the rear of the compute card.  I have both elements set to 24/7 with no sleep or hibernate.  This is in a Home lab setting and works perfect for my needs.  Dual Xeon Nuc 9 with 64gb DDR4 ECC each and 2- 1tb NVMe in Raid 1 each.  Power draw is under 200 watts at full load.Thanks to OEM XS inc for selling these.  Quick shipping,arrived New and it works.