This is the hardware that connects to the Lumia 950 or the 950 XL. It has a DIsplayPort, an HDMI connector, DisplayPort over USB-C capabilities, two USB 2.0 ports, and a USB 2.0 high current charging port.
Connect a keyboard and mouse to turn the phone into a PC. If you don't have a keyboard and mouse handy, you could still use your phone to control your connected screen, and swipe your finger around the phone's screen to move the cursor on the secondary screen. Your phone also doubles as a keyboard.