How to Speed up your iMac with a NVMe 960EVO M.2 SSD - YouTube
How to Install/Upgrade the PCIe SSD in a 27-inch iMac (Late 2013) iMac14,2 - YouTube
Amazon.com: OWC 240GB Aura Pro X2 NVMe SSD Upgrade Kit Compatible with Select 27" and 21.5" iMac Models (Late 2013 - Current) : Electronics
Apple iMac SSD Upgrade — Epoch Business IT Solution
NVME 512GB SSD For Apple iMac 21.5 A1418 EMC 2638 Late 2013 3 Years Warranty | eBay
How to Upgrade/Replace the PCIe SSD in a 21.5-inch iMac (Late 2013) iMac14,1 iMac14,3 - YouTube
Amazon.com: Sintech M.2 nVME SSD Adapter Card Upgrade Kits,Compatible for MacBook Air(2013-2017 Year) and MacBook PRO(Late 2013-2015 Year,iMac : Electronics
Apple iMac 21.5 A1418 27" A1419 128GB SSD Hard Drive (Late 2013) 2014 2015 2017 | eBay
iMac 27 2012-2015 Hard Drive Replacement with SSD
Apple iMac 21.5” SSD Upgrade (2013-2015) HDD To Solid State Drive (SATA) | Step By Step - YouTube
Amazon.com: INDMEM NVMe PCIe SSD 256GB 3D TLC NAND Flash Hard Drive Replacement for Mid 2013-2017 MacBook Air, Late 2013 - Mid 2015 MacBook Pro Retina, Late 2013-2017 iMac, 2013 Mac Pro, 2014 Mac Mini : Electronics
Hard Lesson Learned With Late-2013 Apple Products Containing Lesser Performing 128GB SSDs | The SSD Review