Amazon.com: OWC 8GB (2 x 4GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S08P) : Everything Else
LEVEN DDR4 8GB KIT (2x4GB) 2666MHz PC4-21300 CL19 Unbuffered Non-ECC 1.2V UDIMM 288 Pin PC Computer Desktop Memory Module Ram Upgrade- Lares(JR4UL2666172408-4Mx2) at Amazon.com
Corsair Vengeance LPX 8GB (1 x 8GB) DDR4 DRAM 2400MHz C16 (PC4-19200) Memory Kit - , Vengeance LPX Black at Amazon.com