16GB -2x8GB Memory Ram Upgrade for 27" Apple iMac-13.2 Core i5 2.9GHz Late 2012 | eBay
Timetec 16GB KIT(2x8GB) Compatible for Apple Late 2015 iMac (27-inch w/Retina 5K Display) DDR3L 1867MHz / 1866MHz PC3L-14900 2Rx8 CL13 1.35V 204 Pin SODIMM Memory Module MAC RAM Upgrade for iMac 17,1
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
Apple's 27" iMac Late 2012 model. How to upgrade the ram to 16GB - YouTube
Apple's 2012 iMac: Ready for its close-up (pictures) - CNET