Apple iMac 21.5" Core i5-4570R 2.70 GHz, 8GB RAM, 1TB HDD, 10.15.6 Lat – Pc Retro Shop
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
Apple iMac 21.5" Late 2013 Core i5 2.7GHz 8GB RAM 1TB HDD MacOS Big Sur 11.5.7 | eBay
iMac RAM Upgrade mixing different memory sticks: 27” iMac late 2013 - YouTube
Install memory in an iMac - Apple Support
Apple iMac 21.5" Core i5-4570R 2.70 GHz, 8GB RAM, 1TB HDD, 10.15.6 Lat – Pc Retro Shop