Adamanta 16GB (1x16GB) Memory Upgrade for 2020 Apple iMac 27" w/Retina 5K Display, 2019 Apple iMac 27" w/Retina 5K Display, 2018 Apple Mac Mini DDR4 2666Mhz PC4-21300 SODIMM 2Rx8 CL19 1.2v DRAM
How to: 27-inch 5K iMac (2019) 128GB RAM Upgrade - Save $$$! - YouTube
Apple iMac 27" ME088LL/A Late 2013 - 8GB RAM - 1TB HDD - 3.2GHz Intel Core i5-4570 (Scratch and Dent) - Walmart.com
Install memory in an iMac - Apple Support
128GB Memory Upgrade for 2019-2020 Apple iMac (27-Inch)