How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
27" iMac, Apple iMac (iMac11,3), Intel Core i5 2.80GHz Processor, 8GB RAM, 1TB HDD, DVD-RW, 2560x1440 Screen Resolution, Mac OS X 10.11.3 (El Capitan), No Keyboard/Mouse Or Power Cable, Screen Surround And
8GB [2x4GB] DDR3-1333 RAM Memory Upgrade Kit for The Apple iMac 11,2 (21.5-inch, 3.2GHz, MC509LL/A) Intel Core i3 (Genuine A-Tech Brand) at Amazon.com
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
27" iMac, Apple iMac (iMac11,3), Intel Core i5 2.80GHz Processor, 8GB RAM, 1TB HDD, DVD-RW, 2560x1440 Screen Resolution, Mac OS X 10.11.3 (El Capitan), No Keyboard/Mouse Or Power Cable, Screen Surround Top
A-Tech for Apple 16GB Kit 2 x 8GB PC3-10600 1333Mhz Mac Mini iMac MacBook Pro Late 2011 A1286 MD311LL/A A1297 MC511LL/A A1312 MC309LL/A A1311 MC812LL/A MC813LL/A MC814LL/A MC815LL/A A1347 Memory RAM at
16GB 2X 8GB DDR3 RAM MEMORY FOR APPLE IMAC MODEL# IMAC11,2 IMAC11,3 A1311 A1312 | eBay