G.Skill 32GB DDR4 Trident Z Royal Silver 4000Mhz PC4-32000 CL17 1.35V Quad Channel Kit (4x8GB) at Amazon.com
G.Skill Trident Z NEO Series 32GB (2 x 16GB) 288-Pin SDRAM DDR4 4000 (PC4-32000) CL18-22-22-42 1.40V Dual Channel Desktop Memory Model F4-4000C18D-32GTZN at Amazon.com