iMac Intel 21,5" Mid 2011 EMC 2428 - used original spareparts for Macs
Install memory in an iMac - Apple Support
Apple iMac 27" i5 2.7 (Mid 2011) - Technical data and benchmarks
Apple iMac 2.5Ghz i5-2400S (Mid-2011) *No HDD/RAM* – MSU Surplus Store
Install memory in an iMac - Apple Support
How to upgrade RAM on iMac 21.5" 2011 - YouTube
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
Install memory in an iMac - Apple Support
macos - What is the maximum amount of RAM a 2011 MacBook Pro can utilize? - Ask Different
Apple iMac Mid 2011 Price in Pakistan – Used All-in-One Core i5 8 GB RAM 500 GB HDD 1 GB Graphic Card 27″ and 15 Days Warranty - IT International
Maximum memory for 2011 iMac - Ask Different
OWC 8GB (2 x 4GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac, 2011-12 Mac Mini, and 2011-2012 MacBook Pro (Non-Retina Display) Models (OWC1600DDR3S08S) at Amazon.com
Memory Upgrades for Apple iMac 2011 Up to 32GB
iMac 12,2 (27-inch, Mid 2011)
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