MacBook M.2 NVME Upgrade Adapter - Micro Connectors, Inc.
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
A list of successful iMac 27" (2012-2019) SSD upgrades | Page 39 | MacRumors Forums