One of the interesting thing that i can use with the Mikrotik
#RDS2216 and its many U.2 7mm slots, is the older NVMe M.2 sticks lying around (having been replaced by faster and larger M.2 sticks). The cheap
#StarTech M.2 to U.2 7mm adapter is perfect for this.
Old M.2 just have a very long life..