16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late
HOW I UPGRADED MY iMAC 21.5in Late 2013 MODEL (SSD & RAM UPGRADE) - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Teardown of new 21.5-inch iMac surprisingly reveals user-upgradable RAM, modular CPU - 9to5Mac
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
Apple iMac (21.5-inch, Late 2013) Silver 8GB RAM, 1TB HDD Sell on Consignment - One Bite Technology - St. Albert