Apple 1TB (2x512GB) PCIe Flash SSD Kit for 2017 Apple iMac Pro 656-061A EMC 3197 | eBay
OWC DIY Drive Upgrade/Install Kits for Apple iMac Models
OWC SSD Upgrade Kits for 21.5-Inch iMac (2013 - 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