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
iMac 2012 internal storage upgrade
How to Upgrade iMac Hard Drive or SSD 2012-2022: EveryMac.com