StarTech.com USB 3.0 to Dual HDMI Adapter, 1x 4K 30Hz & 1x 1080p, External Video & Graphics Card, USB Type-A to HDMI Dual Monitor Display Adapter Dongle, Supports Windows Only, Black - USB to Dual HDMI Adapter (USB32HD2) - adapter cable - HDMI / USB - TAA

This USB to HDMI Dual Monitor adapter lets you add two independent HDMI displays to your computer using a single USB 3.0 port. One of the HDMI ports can output resolutions up to 4K, while the other can output resolutions up to 1920 x 1200.
Adding more displays to your workstation can be difficult, especially if your computer does not support MST or offer many external video ports. This USB to dual HDMI adapter features two video outputs, boosting your productivity by giving you more screen space to work from. With multiple displays you have the freedom to access multiple applications at the same time and reference material on one display while you compose on the other.
One of the ports on this USB video adapter supports resolutions up to 4K at 30Hz, meaning you can connect a 4K monitor, HDTV, or projector to your computer, even if your laptop or desktop video card doesn't natively support 4K output. The USB to HDMI 4K adapter lets you extend or mirror your primary display onto an Ultra HD monitor or television, giving you the additional screen space you need to simplify multitasking and maximize your productivity.
Using the high-bandwidth USB 3.0 interface, this USB 3.0 to HDMI adapter enables smoother scrolling through documents, higher resolutions and better overall performance than earlier USB adapters. This video adapter is intended to support all of your business applications including web browsing, e-mail, spreadsheets and presentations. You can also leave your system video card available for more demanding applications such as gaming or CAD design, while you use the USB monitors for reference material.