How to Install a PCIe SSD in a 27-inch iMac (2019)
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
hard drive - iMac 27" late 2012 SSD upgrade - Ask Different