Apple says it should give 2.8x faster graphics performance on the 15-inch MacBook Pro and 8x faster on the 13-inch. Featuring the Radeon Pro 580 graphics processor with 8GB of GDDR5 memory, the Blackmagic eGPU sports two Thunderbolt ports, four USB 3 ports, four UBS 3 ports, one HDMI 2.0 port, and 85W power delivery.
As noted by The Verge, it's an all-in-one eGPU, unlike other chassis-style designs that require you to supply your own card. That makes it less flexible and upgradable than other options, but allows for a more integrated, quieter design with a smaller footprint. Apple says you can “pair the Blackmagic eGPU with the stunning resolution and immaculate visuals of the LG UltraFine 5K Display for the ultimate Mac setup.”