NEMIX RAM 32GB (4x8GB Upgrade) DDR3-1333 PC3-10600 204-Pin SODIMM Memory for Apple MacBook Pro Early/Late 2011, iMac Mid 2010 27 inch 4-Core, iMac Mid 2011 21.5/27” , Mac Mini Mid 2011 at Amazon.com
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
Sold - 21.5" iMac Mid 2011 // $495 - Boulder Mac Repair
Apple iMac 2.5Ghz i5-2400S (Mid-2011) *No HDD/RAM* – MSU Surplus Store
Simmtec 4GB RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010, Mid 2011, Late 2011), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Module at Amazon.com
How to Upgrade Memory in a 21.5-inch or 27-inch iMac (Mid 2010) - YouTube
Apple iMac review (mid 2011) - The Verge
2011 Apple iMac 27" Intel i5 2.7GHz 8GB RAM 512GB SSD AMD Radeon HD 6770M | eBay
Apple iMac 21.5-inch Mid 2011 2.5GHz Intel Core i5 (MC309LL/A) – UNICOM, Inc.
HOW TO: Upgrade The RAM to 32GB on a Mid-2011 21.5inch iMac - YouTube
Memory RAM Upgrade for Apple iMac 21.5-inch Mid 2011 4GB/8GB DDR3 SODIMM | eBay
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 21.5" Mid 2011 How To Change/Upgrade Your Ram For Better Performance 2014 - YouTube