32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
iMac 21.5 Inch 3.06GHz Intel Core i3 Mid-2010 MC508LL/A
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
A-Tech 32GB (4x8GB) RAM for Apple iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
Install memory in an iMac - Apple Support
A-Tech 8GB RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Module at Amazon.com
How To Upgrade RAM in a Mac | Macworld
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
RAM upgrade considerations for iMac systems - CNET