Apple iMac Mid 2011 21.5-inch 2.8GHz Core i7 Apple Memory & SSD Upgrades
Memory Upgrades for Apple iMac 2011 Up to 32GB
Amazon.com: OWC SSD Upgrade Kit for 2011 21.5-inch iMacs, Mercury Electra 1.0TB 6G SSD, 18" SATA III 6Gbps Data Cable, Installation Tools and iMac Screen Adhesive Tape Set : Electronics
How to Upgrade iMac Hard Drive (2009, 2010, 2011): EveryMac.com
2011 IMAC SAMSUNG 1TB 850 PRO SSD UPGRADE - YouTube
Apple iMac 21" Mid-2011 Hard Drive Replacement - YouTube