Timetec 8GB Compatible for Apple DDR3L 1600MHz PC3L-12800 for Mac Book Pro (Early/Late 2011,Mid 2012), iMac(Mid 2011,Late 2012,Early/Late 2013,Late 2014,Mid 2015), Mac Mini(Mid 2011,Late 2012) MAC RAM at Amazon.com
Apple iMac 21.5 inch Desktop - MF883LL/A (June, 2014) for sale online | eBay
Macworld
Apple iMac 21.5" All-in-One Desktop Computer i3 3.07GHz 4GB Ram 500GB HDD Mac OS High Sierra MC508LL/A w/ Keyboard & Mouse