Apple iMac 21.5" Late 2013 Core i5 2.7GHz 8GB RAM 1TB HDD MacOS Big Sur 11.5.7 | eBay
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Can you upgrade the RAM in the 27-inch iMac? | iMore
Install memory in an iMac - Apple Support
iMac Intel 21.5" EMC 2638 Teardown - iFixit
Apple iMac 21.5" Core i5-4570R 2.70 GHz, 8GB RAM, 1TB HDD, 10.15.6 Lat – Pc Retro Shop
Apple Updates iMac with Faster CPUs and 802.11ac Wi-Fi - TidBITS
Pre-Owned Apple iMac 21.5-inch Desktop "Core i5" 2.9 (Late 2013) 8GB Memory 1TB HDD ME087LL/A - Best Buy
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
HOW I UPGRADED MY iMAC 21.5in Late 2013 MODEL (SSD & RAM UPGRADE) - YouTube
I got a FREE 2013 iMac 21.5 with internal upgrades including Samsung evo ssd and 16gigs of ram. Then used open legacy patcher to install Mac OS Venture 13.5 beta. : r/osx