File:Radeon Pro 580X MPX Module bottom.jpg

Summary
Bottom view of a Radeon Pro 580X MPX Module (with PCIe connector at left, and MPX connector at right) developed by AMD for the 3rd-generation Mac Pro. The MPX connector interfaces with the USB-C / Thunderbolt 3 ports on the Mac Pro itself.

Source

 * Apple AMD Radeon Pro 580X 8GB RAM MPX Module for 2019 Mac Pro 7,1 A1991 by ipowersale, eBay. 2022-04-29.