I am looking for some form of economic device that would let me power a 4th monitor from my laptop. It currently powers 3 but I bought a monitor stand that can hold 4 in a 2x2 grid. It would have to connect through USB-3, USB-C, or DP. It's just doing excel, calendar, and other Microsoft products. So I'm not looking for a graphical workhorse. Just additional 1920x1080 real estate. My laptop is a HP EliteBook 840 G4 https://support.hp.com/us-en/document/c05349510 .