CMS 16GB (2X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I5 3.4 27-Inch (Late 2013) Me089Ll/A - A7 at Amazon.com
Install memory in an iMac - Apple Support
iMac 2013 Model Ram Upgrade - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Install memory in an iMac - Apple Support
How to Upgrade iMac RAM: 2012-2022: EveryMac.com
NEMIX RAM 16GB Kit (2x8GB Upgrade) DDR SODIMM PC for Apple MacBook Pro Mid 2012 / iMac Late 2012 / iMac 2013, Late 2014, Mid 2015, Mac Mini Late 2012 16GB (2X8GB) - Walmart.com