The Mobile Pixels DUEX Pro Portable Dual Monitor clips onto the side of your laptop. In a special deal for Bleeping Computers, you can get it for just $180 using the promo code SAVEDUEXPRO. The 12.5-inch display comes with metal adhesive plates which provide a strong attachment to your laptop. It works seamlessly with Windows, Mac, Chrome, and Linux machines. IPS technology ensures you see perfect colors from almost any angle, and the attachment point has a hinge action.
Source: https://www.bleepingcomputer.com/offer/deals/this-portable-1080p-display-is-perfect-for-multitasking-on-the-go/