Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
A First Look At The 2012 21.5-inch iMac, And How It Compares To Generations Past | TechCrunch
DDR3 1600MHZ PC3-12800 SODIMM for Apple iMac 2012 - 2013 (13,2 14,2)
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
Soundporium Music Store - Apple Imac 2012 21.5 inch Intel Core i5 / Processor 2.7 GHz / 1TB SSD / 8GB RAM / MacOS El Capitan - Military & First Responder Discounts | GovX
Apple's 2012 iMac: Ready for its close-up (pictures) - CNET
iMac RAM for Model 13.2 to 15.1| DDR3-1600MHz | 8GBx2 | MacMemory.com
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