This is 6x 6.4TB NVME which are about 15mm height mounted with a 3D printed bracket using the four holes 45Drives supplied on the rear (and which seem to take M4 sized screws and heatset inserts).
I’m looking forward to doing something like that eventually as well with 4 drives. There was another 3D print drive mount posted here before but the drives were rotated so they wouldn’t get good airflow. Yours solves that problem.
Bambu Lab X1E and their own ABS filament — so far so good on temperatures, the NVME gets hotter than the CPU cooler by some margin. I don’t think printing one of these in PLA would be a good choice as I think surface contact temperature of the NVME might exceed the glass transition temperature of PLA.