maxupgrades.com: Single SSD Drives kit for iMac 27 inch 2012 Models with SATA Blade SSD Module / Heatsink/ Power Cable and DATA Cables for [SSD + HDD] with iMac Adhesive LCD Tape
240GB OWC 6G SSD and HDD Kit for 27-inch iMac all 2012 - Mid 2019
661-7167 Apple 768GB SSD (Solid State Drive) Flash Storage for iMac 27" Late 2012 655-1796A