G.SKILL, 2 x 8 GB (16GTZR), Black Trident Z RGB 16 Go (2X 8 Go) DDR4 4000 MHz CL17 at Amazon.com
G.SKILL 16GB (2 x 8GB) TridentZ Series DDR4 PC4-32000 4000MHz Memory Desktop Memory Model F4-4000C18D-16GTZKW at Amazon.com
G.SKILL 64GB (8 x 8GB) TridentZ RGB Series DDR4 PC4-32000 4000MHz Intel X299 Desktop Memory Model F4-4000C18Q2-64GTZR at Amazon.com
v-Color Prism Pro RGB SCC(2+2) Kit 16GB (2x8GB) 4000MHz (PC4-32000) DDR4 RAM with RGB Filler Kit Gaming Desktop Memory Module Ram Upgrade (SCC-TL8G40819D-E6PRSWK) at Amazon.com
Amazon.com: Thermaltake TOUGHRAM XG RGB DDR4 4000MHz 16GB (8GB x 2) 16.8 Million Color RGB Alexa/Razer Chroma/5V Motherboard Syncable RGB Memory R016D408GX2-4000C19A : Everything Else
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
HyperX Predator Black 16GB 4000MHz DDR4 CL19 DIMM (Kit of 2) XMP (HX440C19PB3K2/16) at Amazon.com