Timetec 32GB KIT(2x16GB) Compatible for Apple DDR4 2666MHz / 2667MHz for Mid 2020 iMac (20,1/20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K, Late 2018 Mac Mini (8,1) PC4-21333 /PC4-21300 MAC RAM at Amazon.com
Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB
How to upgrade the 27-inch 5K iMac (2019) with a massive 128GB of RAM [Video] - 9to5Mac
Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB
The 27-inch iMac 2019's RAM may be upgraded to 128GB - NotebookCheck.net News
OWC Announces RAM Upgrades for New 27-Inch 5K iMacs - MacRumors