A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Bringing new life into this free late 2012 iMac is going great so far now that I know I can at least install Big Sur on it. SSD and a proper keyboard
iMac | 3.1 GHz Intel i7 | 21.5 Inch | Late 2012 - Techable.com
Apple iMac 27″ Intel i7 (Late 2012) | Dynemac
Apple iMac 21.5-inch (December 2012) review: The smaller iMac Windows PCs can pick on - CNET