32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
How To Upgrade RAM in a Mac | Macworld
hardware - Can I add different size RAMs to iMac 5K? - Ask Different
NEMIX RAM 32GB Kit (4x8GB 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