This family covers an unusually wide span for a single product name: Kingston's ValueRAM DDR4 SODIMM runs from older, slower-rated grades up to the fastest the line offers. That spread is broader than most families in the catalogue, so the specific listing matters more here than usual.
Speed runs from 2666 MT/s down to considerably older ratings, with CL19 loosening at the slower end of the range, and capacity spans from smaller single-stick kits up to a 16GB maximum. Since laptops and small-form-factor boards often have fixed, non-upgradeable speed ceilings, it's worth checking what your system's manual actually supports before assuming the fastest-rated kit here will run at its full speed.
This is SODIMM DDR4, built for laptop and small-form-factor sockets rather than desktop boards — confirm your system takes SODIMM before ordering, since it will not fit a UDIMM slot.