Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3L 1600MHz PC3L-12800 CL11 for iMac (Mid 2011, Late 2012, Late 2013, Late 2014 Retina 5K, Mid 2015 Retina 5K) SODIMM Memory Module MAC RAM Upgrade at Amazon.com
How to Upgrade the Main Drive in a 21.5-inch iMac 2012-2015 (iMac13,1 iMac14,1 iMac14,4 iMac16,1) - YouTube
iMac Intel 21.5" and 27" (Late 2012-Early 2019) SSD Temperature Sensor
How to Install/Upgrade the SSD Card Slot of a 27-inch iMac (Late 2012) iMac13,1 - YouTube