Thunderbolt 3 (USB-C) to Apple Thunderbolt cable
My iMac has a Thunderbolt 3 (USB-C) port, which is a small oval shape.
My accessory device has an Apple Thunderbolt port, which is a larger rectangle shape.
Both ports are Thunderbolt 3, but each has a different port shape.
Is there a cable or adapter to connect these two things?
iMac 27" 5K, macOS 10.14