Like other A-Tech UDIMM families, this one keeps speed and CAS constant and spreads capacity instead — and it spreads further than most, running from a single small stick meant as a first upgrade up to a four-module set built for boards with every slot filled.
4×32GB of DDR4 UDIMM gives 128GB in this listing, all rated at the family's shared 3200 MT/s CL22, unbuffered and non-ECC for standard desktop boards. At the small end this is a straightforward single-stick addition to an existing system; at the large end, four populated slots put more demand on a board's memory controller than the same total split two ways would, so check how many slots your board has free before choosing a module count from the top of this range.