Kingston 16GB DDR4 SDRAM Memory Module at Amazon.com
Kingston 16GB DDR4 2666MHz ECC Module at Amazon.com
Arch Memory AM-D4ECSO-2666-16G 16GB 260-Pin DDR4 2666 MHz ECC So-dimm RAM for Synology NAS Systems
G.Skill Ripjaws V Series 16GB (2 x 8GB) 288-Pin SDRAM (PC4-21300) DDR4 2666 CL15-15-15-35 1.20V Dual Channel Desktop Memory Model F4-2666C15D-16GVR at Amazon.com