G.Skill Trident Z RGB Series 16GB (2 x 8GB) 288-Pin SDRAM DDR4 4000 (PC4-32000) CL18-22-22-42 1.35V Dual Channel Desktop Memory Model F4-4000C18D-16GTZRB at Amazon.com
G.SKILL Trident Z Royal Elite DDR4-4000 MHz CL14 2x8 GB Review | TechPowerUp
G.Skill Trident Z Royal 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-32GTRS at Amazon.com