INDMEM 1TB NVMe PCIe Gen3x4 Internal SSD per MacBook Air 2013-2017, MacBook Pro Retina 2013-2015, iMac 2013-2017, Mac Pro 2013, Mac Mini 2014 : Amazon.it: Informatica
Upgrade your iMac with OWC, 2017 4K Retina Edition
Genuine Apple 4TB (2x2TB) PCIe SSD for: 2017 iMac Pro A1862; 2019 Mac Pro A1991 | eBay
iMac Pro (2017) 1TB SSD Upgrade - NiwTech
How to Upgrade iMac Pro SSD (Replace Storage): EveryMac.com
Base model iMac Pro teardown sheds more light on its upgrade potential - 9to5Mac