Aegis is G.Skill's plain-finish DDR4 line — no RGB, a basic black heatspreader, positioned under the Trident and Ripjaws families as the no-frills option. It's sold across single sticks, pairs, and quad-module sets, all under the same name, with the speed grade as the thing that actually varies inside it.
1×16GB rated at 3200 MT/s CL16 gives 16GB in this listing, while other Aegis kits at a lower grade carry the same capacity and module count at a slower timing — a four-module set also draws on all of a board's slots at once, a heavier load on the memory controller than a two-stick kit of the same total size. All of it is DDR4 UDIMM for standard desktop boards, unbuffered and built for consumer platforms rather than anything requiring registered memory.