How to Install/Upgrade the PCIe SSD in a 27-inch iMac (2019) iMac19,1 - YouTube
Amazon.com: Timetec 512GB MAC SSD NVMe PCIe Gen3x4 3D NAND TLC Read Up to 2,000MB/s Compatible with Apple MacBook Air (2013-2015, 2017), MacBook Pro (2013-2015), iMac (2013-2019), Mac Pro (2013), Mac Mini (2014) : Electronics
Performance, features and verdict - Apple iMac (27-inch, 2019) - Page 2 | TechRadar
OWC Accelsior 1A Apple Factory SSD to PCIe Adapter Card
Timetec 256GB MAC SSD NVMe PCIe Gen3x4 3D NAND TLC Internal SSD Compatible with Apple MacBook Air (2013-2015, 2017), MacBook Pro (2013-2015), iMac (2013-2019), Mac Pro (2013), Mac Mini (2014) - Walmart.com
Apple 2TB SSD sspolaris MZ-KKW2T00/0A8 iMac 2019 2017 2015 655-1996 Original | eBay
Amazon.com: LEVEN 1TB Mac Upgrade NVMe SSD PCIe Gen3x4 Compatible with Apple MacBook Air (2013-2017) & Pro (2013-2015), Mac Mini (2013) & Pro (2014), iMac (2013-2019) : Electronics
M.2 NVMe SSD adapter for Apple MacBook Air/Pro, iMac, Retina iMac 4K/5K, Mac Pro | eBay
Upgrading an older iMac's PCIe SSD: Third-party solutions that save you beaucoup bucks | Macworld
Amazon.com: LEVEN 1TB Mac Upgrade NVMe SSD PCIe Gen3x4 Compatible with Apple MacBook Air (2013-2017) & Pro (2013-2015), Mac Mini (2013) & Pro (2014), iMac (2013-2019) : Electronics
SOLVED: Can I attach m.2 ssd heatsink to the 2019 iMac 27inch? - iMac Intel 27" Retina 5K Display 2019 - iFixit
Timetec 512GB MAC SSD NVMe PCIe Gen3x4 3D NAND TLC Read Up to 2,000MB/s Compatible with Apple MacBook Air (2013-2015, 2017), MacBook Pro (2013-2015), iMac (2013-2019), Mac Pro (2013), Mac Mini (2014) - Newegg.com
Where is my iMac A1419 SSD? - Ask Different
A list of successful iMac 27" (2012-2019) SSD upgrades | Page 39 | MacRumors Forums