iMac Intel 21,5" Mid 2011 EMC 2428 - used original spareparts for Macs
CMS 16GB (4X4GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I3 3.06 21.5-Inch (Mid-2010) - A28 at Amazon.com
Install memory in an iMac - Apple Support (IN)
RAM Upgrade for iMac Mid 2011 21.5-inch | MacRumors Forums
How to upgrade RAM / Memory on a 2010 iMac Core i3 i5 i7 (21.5in & 27in) - YouTube
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
Imac 2011 Max Ram Poland, SAVE 33% - piv-phuket.com
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac