AITC 16GB (2 x 8GB) Laptop Memory Module Upgrade DDR4 2666MHz SO-DIMM, Notebook Ram Module at Amazon.com
Crucial 16GB Single DDR4 2666 MT/s (PC4-21300) CL19 DR x8 SODIMM 260-Pin for Mac - CT16G4S266M at Amazon.com
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
parts-quick 16GB Memory for Synology DS3617xs Compatible DDR4 ECC Unbuffered SODIMM RAM (Equivalent to Synology D4ECSO-2666-16G) at Amazon.com