Refurbished: Apple A Grade Desktop Computer 27-inch iMac A2115 2019 MRR12LL/A 3.7 GHz Core i5 (I5-9600K) 32GB RAM 1TB SSD Storage Mac OS Include Keyboard and Mouse - Newegg.com
Install memory in an iMac - Apple Support
iMac 27in (2019) Review: The Same But Better | Macworld
Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB
Apple iMac 27 Inch 5K 2019 3.7 GHz 6-Core i5 2TB Fusion 16GB RAM 8GB G – Quality Macs
Apple iMac 5K 27-inch (Mid 2019) 3.6GHz i9 128GB RAM 4TB SSD - Buy Refurbished iMac 2019 at Techable
How to upgrade the 27-inch 5K iMac (2019) with a massive 128GB of RAM [Video] - 9to5Mac