Review on 🌟 High-Quality StarTech.com Mini DisplayPort to HDMI Adapter for 4K 60Hz Video - Active mDP 1.4 to HDMI 2.0 Converter - Compatible with Mini DP or Thunderbolt 1/2 Mac/PC - Ideal for HDMI Monitor/TV/Display - mDP to HDMI Dongle (MDP2HD4K60S) by Stephanie Love

I bought this to add a third external display to my mid 2015 15.5 inch Macbook Pro with discrete graphics. The old MBP with NVidia graphics could support three external displays simultaneously, but a consequence of Apple's move to Radeon cards is that they only have enough power to run two external displays at once. some power is drawn from the monitor, not the graphics card My 3rd display works and I love it!