CUDIMM is a newer DDR5 module type that carries its own onboard clock driver, and this ValueRAM family is built specifically in that format rather than as a standard UDIMM — it needs a board whose chipset explicitly supports CUDIMM/CKD memory, not just any DDR5 socket.
This one is sold as a single 1×16GB module, 16GB, rated 6400 MT/s CL52. As with the rest of ValueRAM, these are single sticks rather than kits, so a dual-channel build needs two purchased separately — and because the format is CUDIMM, that second module should be checked against the same board support list before assuming it will run at 6400 MT/s.
This is CUDIMM DDR5; installing it in a board that only supports conventional UDIMM is not guaranteed to work, so confirm CUDIMM support before buying.