HP S1 Single RAM 16GB DDR4 2666MHz CL19 Laptop Memory - 7EH99AA#ABC at Amazon.com
v-Color 32GB (2 x 16GB) ECC SO-DIMM DDR4 2666MHz (PC4-21300) for NAS Micro Server/Workstation/Compatible with Synology 21 Series 2Rx8 CL19 1.2V (TES416G26D819K-VKC) at Amazon.com
Sam Original 16GB (1x16GB) DDR4 2666MHz PC4-21300 SODIMM 2Rx8 CL19 1.2v 260-PIN Laptop Notebook Memory Module RAM Upgrade M471A2K43CB1-CTD Adamanta at Amazon.com
Patriot Signature Line DDR4 16GB (2 x 8GB) 2666MHz (PC4-21300) UDIMM Dual Kit Memory Kit PSD416G2666K at Amazon.com
Arch Memory AM-D4ECSO-2666-16G 16GB 260-Pin DDR4 2666 MHz 2R ECC So-dimm RAM for Synology NAS Systems at Amazon.com