OWC Confirms New Low-End 27-inch iMac Can Be Fitted With 64GB RAM - MacRumors
CMS 32GB (4X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Retina 5K 27-Inch (Late 2014) Core I5/I7 - A6 at Amazon.com
Memory Upgrades for iMac w/ Retina 5K Display Late 2015
Refurbished 27-inch iMac 3.6GHz 10-core Intel Core i9 with Retina 5K display - Apple
Install memory in an iMac - Apple Support
Apple A Grade Desktop Computer 27-inch iMac A2115 2019 MRR02LL/A 3.6 GHz Core i9 (I9-9900K) 16GB RAM 2 TB SSD Storage Mac OS Include Keyboard and Mouse - Walmart.com