G.Skill Trident Z Series 64GB (2 x 32GB) 288-Pin SDRAM (PC4-25600) DDR4 3200 CL16-18-18-38 1.35V Dual Channel Desktop Memory Model F4-3200C16D-64GTZR at Amazon.com
Corsair CMK64GX4M4A2666C16 Vengeance LPX 64GB (4x16GB) DDR4 2666 C16 Desktop Memory Kit for DDR4 Systems at Amazon.com
OWC 64GB (4 x 16GB) PC21300 DDR4 2666MHz SO-DIMMs Memory Compatible with Mac Mini 2018, iMac 2019 and up, and Compatible PCs (OWC2666DDR4S64S) at Amazon.com
CORSAIR Vengeance LPX 64GB (4x16GB) DDR4 3200 (PC4-25600) C16 1.35V Desktop Memory - Black at Amazon.com
A-Tech 64GB Kit (2x32GB) RAM for Apple iMac & Mac Mini (2018, 2019 & 2020) | DDR4 2666 MHz SODIMM PC4-21300 / PC4-21333 260-Pin SO-DIMM Memory Upgrade at Amazon.com
Samsung 32GB DDR4 2666MHz RAM Memory Module for Laptop Computers (260 Pin SODIMM, 1.2V) M471A4G43MB1 at Amazon.com
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