OWC SSD Upgrade Kit For 2010 27-inch iMacs, OWC Mercury Electra 250GB 6G SSD, 18" SATA III 6Gbps data cable, SSD Power Cable, Installation tools and iMac screen adhesive tape set :
Upgrading a 27-inch iMac 5K to 14 terabytes - Replacing the Fusion Drive with both a SSD and an harddisk