A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz SODIMM PC3-12800 204-Pin SO-DIMM Max Memory Upgrade at Amazon.com
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
How to install RAM - Memory on a Apple iMAC 27" 5K - YouTube
How to upgrade iMac (2020) RAM and save up to $2000 - 9to5Mac
Opened up 2012 21.5 iMac for SSD upgrade. | MacRumors Forums