iMac (27-inch, Late 2012) - Technical Specifications
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz SODIMM PC3-12800 204-Pin SO-DIMM Max Memory Upgrade at Amazon.com
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
Apple iMac review (2012) | Engadget
16GB (2x8GB) RAM Memory Upgrade For Apple iMac 27'' A1419 Late 2012 2013 | eBay