12GB OWC Memory Upgrade Kit (1 x 4GB + 1 x 8GB) 1600MHz PC3-12800 DDR3L SO-DIM | Megamac
OWC 32GB (2 x 16GB) PC21300 DDR4 2666MHz 260pin SO-DIMMs Memory Ram Module, Compatible with Mac Mini 2018, iMac 2019 and up, and Compatible PCs, (OWC2666DDR4S32P) at Amazon.com
16MB OWC Memory Upgrade Module
How to upgrade iMac (2020) RAM and save up to $2000 - 9to5Mac