OLOy DDR4 RAM 64GB (2x32GB) 2666 MHz CL19 1.2V 260-Pin Laptop Gaming SODIMM Upgrade for 2019/2020 iMac 27-inch with Retina 5K Display Late 2018 Mac Mini (MD4S322619MZDC) at Amazon.com
DDR4 RAM】 Gigastone Desktop RAM 64GB (2x32GB) DDR4 64GB DDR4-3200MHz PC4-25600 CL22 1.2V 288 Pin Unbuffered Non ECC UDIMM for PC Computer Desktop Memory Module (Desktop ONLY) at Amazon.com
Crucial RAM 64GB Kit (2x32GB) DDR4 3200MHz CL22 (or 2933MHz or 2666MHz) Desktop Memory CT2K32G4DFD832A at Amazon.com