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
Amazon.com: Apple iMac MNE92LL/A 27 Inch, 3.4 GHz Intel Core i5, 8GB RAM, 1TB Fusion Drive, Silver (Renewed), Mac OS : Electronics
iMac RAM Upgrade mixing different memory sticks: 27” iMac late 2013 - YouTube