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
Mushkin Enhanced Essentials 32GB (2 x 16GB) 260-Pin DDR4 SO-DIMM DDR4 2133 (PC4 17000) Laptop Memory Model MES4S213FF16G28X2 - Newegg.com