Many of us are used to working on laptops. They’re convenient, yet their screens aren’t always big enough for every task. But an extra computer monitor isn’t something you can just throw in your bag when you’re on the go. Or can you? Consumer Reports explains how some new tech makes that possible.

For some people, a lightweight portable monitor could make life a lot easier. They let you work in several windows at once or mirror what’s on your screen for a group presentation. And they’re powered by a cord connected to your laptop, so no plugging them into the wall.

Some even let you add touchscreen and stylus capabilities to a laptop that lacks those features. Consumer Reports tech editors took a look at six 15.6-inch models, and while they often don’t match the display quality of a laptop, they can still be very useful.

Although some can be pricey, costing more than $300, CR finds a few models in the lower end of the price range you might want to consider.

The Lepow Z1-Gamut for $140 ($160 in Canada) is the Editor’s Pick. It’s thin, light, and connects quickly and easily to your laptop and several other devices. And its display is on par with more expensive models.

If you prefer a touchscreen, the model from ViewSonic TD1655 for $270 ($360 in Canada) is one of the least expensive options out there. It comes with a stylus, and its touchscreen is responsive and works well. But check for compatibility—it won’t work with all Windows laptops.

Finally, if you’re on a tight budget, but still need more screen space, consider our Budget Pick KYY Portable Monitor for $130 ($280 in Canada). It connects easily to Mac, Windows, Android, iPad, and Nintendo Switch devices. And while its display isn’t as good as the Lepow, CR says it does get the job done without breaking the bank.

CR says the higher a portable monitor’s brightness level—measured in nits—the better off you’ll be, especially if you’re planning to use it in the sun.