Timetec 16GB KIT(2x8GB) Compatible for Apple Late 2015 iMac (27-inch w/Retina 5K Display)
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 iMac 27" - Late 2012 Reviews, Pros and Cons | TechSpot
16GB (2x8GB) RAM Memory Upgrade For Apple iMac 27'' A1419 Late 2012 2013 | eBay
Install memory in an iMac - Apple Support
27" iMac Offers Easier RAM Upgrade
Apple's 27" iMac Late 2012 model. How to upgrade the ram to 16GB - YouTube