Apple's 27" iMac Late 2012 model. How to upgrade the ram to 16GB - YouTube
DDR3 1600MHZ PC3-12800 SODIMM for Apple iMac 2012 - 2013 (13,2 14,2)
Apple iMac 27" Desktop Core i5-3407S 2.9GHz 8GB RAM 1TB HDD Mojave OS 2012 w/ Keyboard & Mouse
OWC 8GB (2 x 4GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac, 2011-12 Mac Mini, and 2011-2012 MacBook Pro (Non-Retina Display) Models (OWC1600DDR3S08S) at Amazon.com
Apple iMac 21.5" Core i5-4570R 2.70 GHz, 8GB RAM, 1TB HDD, 10.15.6 Lat – PC Retro Shop
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
A First Look At The 2012 21.5-inch iMac, And How It Compares To Generations Past | TechCrunch