How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac
How to upgrade the 27-inch 5K iMac (2019) with a massive 128GB of RAM [Video] - 9to5Mac
Apple A Grade Desktop Computer iMac 21.5-inch 2.3GHZ Dual Core i5 (Mid 2017) MMQA2LL/A 8 GB RAM 1 TB HDD 1920x1080 Display Mac OS Includes Keyboard and Mouse - Walmart.com
iMac Retina 5K: Memory upgrade (RAM)
Can you upgrade the RAM in the 27-inch iMac? | iMore