https://www.theverge.com/circuitbreaker/2018/7/12/17563646/apple-blackmagic-external-gpu-price-release-date

To go alongside the newly updated MacBook Pros, Apple is selling a product for users who need more graphic processing power. Apple worked with cinema company Blackmagic on an external GPU based around a Radeon Pro 580 with 8GB of video memory. Apple says it should give 2.8x faster graphics performance on the 15-inch MacBook Pro and 8x faster on the 13-inch.

The Blackmagic eGPU also has two Thunderbolt 3 ports, four USB 3 ports, and one HDMI 2 port, making it a pretty capable docking station as well. It’s the first eGPU to support Thunderbolt 3 displays like the 5K LG monitor Apple recommends for use with the MacBook Pro.