Gigastone's Game Pro kits are a budget-oriented DDR4 line sold across a fairly wide spread of configurations, from dual-stick kits up to four-module sets at the same or higher total capacity. As with most value-tier DDR4, the appeal here is filling out a system's memory slots cheaply rather than chasing the tightest possible timings.
Within the family, 3200 MT/s is the most common rating, though a couple of listings step up to a faster bin at slightly looser CL16. A four-2×8GB kit will typically run at lower clocks or looser timings than the equivalent two-module capacity on the same board, so check which configuration a listing actually is before assuming two kits of the same 16GB behave identically.
This is standard unbuffered, non-ECC UDIMM DDR4 for desktop boards. Reaching the rated speed requires enabling the XMP profile in BIOS; without it the modules run at a slower JEDEC default.