There are two slots for memory cards in the Z9 and you can either use CF Express Type B or XQD. I had XQD cards that I used while I was shooting with DSLRs (D5 and D850) and so I thought I would use theses cards with Z9 as well. I was so wrong. It might be ok for someone who is shooting only single photos, not in RAW and is not using the camera for video, but as I have already mentioned above, the speed in photography is super important for me as well as to use the full potential of it and so after the first test I immediately purchased CF Express cards. The XQDs were just simply not enough for 20 RAW files per second or for the raw video.