Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3L 1600MHz PC3L-12800 CL11 for iMac (Mid 2011, Late 2012, Late 2013, Late 2014 Retina 5K, Mid 2015 Retina 5K) SODIMM Memory Module MAC RAM Upgrade at Amazon.com
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Best Buy: Apple 21.5" Certified Refurbished iMac Desktop Intel Core i5 1.4GHz 8GB Memory 500GB HDD (2014) Silver MF883LL/A