21.5" iMac Mid-2014 1TB SATA SSD Upgrade – UKSL MacLab
Amazon.com: OWC SSD Upgrade Kit for 2011 21.5-inch iMacs, Mercury Electra 250GB 6G SSD, 18" SATA III 6Gbps Data Cable, Installation Tools and iMac Screen Adhesive Tape Set : Electronics
Amazon.com: OWC Internal SSD DIY Kit For All Apple 21.5" iMac 2011 Models w/ Tools : Electronics