SSD Upgrades for Apple iMac 27-Inch Late 2013 - 2019
8GB 2x4GB DDR3-1600 RAM iMac 27” Late 2013 Memory Direct Takeoff Not Aftermarket | eBay
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
How To Upgrade RAM in a Mac | Macworld
NEMIX RAM 16GB Kit (2x8GB Upgrade) DDR3-1600 SODIMM PC3-12800 for Apple MacBook Pro Mid 2012 / iMac Late 2012 / iMac 2013, Late 2014, Mid 2015, Mac Mini Late 2012 at Amazon.com
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013