Amazon.com: PCIe NVMe Gen3x4 SSD 1TB 512GB 256GB 128GB 3D TLC NAND Flash Hard Drive SSD Replacement for Macbook Air 2013-2017, Macbook Pro Retina 2013-2015, iMac 2013-2017, Mac Pro 2013, Mac Mini 2014 (1TB) : Electronics
Apple iMac 21.5 A1418 27" A1419 256GB SSD Hard Drive (Late 2013) 2014 2015 2017 | eBay
SSD Upgrades for Apple iMac 27-Inch Late 2013 - 2019
128GB FUSION DRIVE PCIe SSD Apple iMac 21.5" A1418,27" A1419 Late 2013,2014,2015 | eBay
How to Install/Upgrade the PCIe SSD in a 27-inch iMac (Late 2013) on Vimeo