Apple iMac 21.5" Core i5-4570R 2.70 GHz, 8GB RAM, 1TB HDD, 10.15.6 Lat – Pc Retro Shop
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Install memory in an iMac - Apple Support
iMac 2013 Model Ram Upgrade - YouTube
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
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
How to upgrade RAM iMac late 2013 21.5inch - break & fix MOVIE - YouTube
Apple 21-inch iMac, late 2013 review | TechRadar
Mac RAM Upgrade, Best iMac Memory Upgrade – Best Reviews
Apple iMac 21.5" All-in-One Desktop Computer Core i5-4570R 2.7GHz 8GB RAM 250GB HDD Mac OS Mojave Late-2013 w/ Keyboard & Mouse