RMSA3300ME78HBF-2666 16gb Pc4 2666MHz DDR4 So-Dimm Non-ECC 260 pin 1.2V Ram Memory for Laptop and All in One Desktop Computer (16gb Pc4 2666MHz DDR4 So-Dimm) at Amazon.com
Amazon.com: Crucial 16GB Single DDR4 2666 MT/s (PC4-21300) DR x8 DIMM 288-Pin Memory - CT16G4DFD8266 : Everything Else
Crucial Memory Bundle with 32GB (2 x 16GB) DDR4 PC4-21300 2666MHz SODIMM (CT2K16G4SFD8266) Compatible with Latitude 5500, 5580, 5590, 5591, 7200, 7280, 7290, 7300, 7390, 7400, 7480, 7490 at Amazon.com
AITC 32GB (2 x 16GB) Laptop Memory Module Upgrade DDR4 2666MHz SO-DIMM, Notebook Ram Module at Amazon.com