How to install RAM - Memory on a Apple iMAC 27" 5K - YouTube
Install memory in an iMac - Apple Support
How to UPGRADE RAM in the (Mid 2017) 5K iMac & save $$$! - YouTube
How to upgrade the RAM on the 27-Inch iMac (2020) | AppleInsider
Apple 27" iMac® with Retina 5K display Intel Core i5 (3.1GHz) 8GB Memory 256GB SSD Silver MXWT2LL/A - Best Buy
Install memory in an iMac - Apple Support
The New 2017 iMac: Notes & Tidbits on RAM - The Mac Observer
A-Tech 64GB (4x16GB) RAM for Apple iMac 2017 27 inch Retina 5K | DDR4 2400MHz SODIMM PC4-19200 2Rx8 1.2V 260-Pin SO-DIMM Memory Upgrade Kit at Amazon.com
16GB -2x8GB Memory Ram Upgrade for 27" Apple iMac-14.2 Core i5 3.2GHz Late 2013 | eBay
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
Install memory in an iMac - Apple Support
Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB