How to add a fast new SSD to your old Mac or MacBook for only $150 - 9to5Mac
OWC Aura Pro X2
Amazon.com: OWC 2TB Aura Pro X2 NVMe SSD Upgrade Kit Compatible with Select 27" and 21.5" iMac Models (Late 2013 - Current) : Electronics
256GB PCIe SSD Install Kit Apple iMac 27 A1419 Late 2013,Mid 2014,2015 Retina 5K | eBay
OWC SSD Flash Storage Upgrade for Mac mini 2014
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