Uber just revealed what may be its most useful feature yet: the ability to actually find your car.

The ride-hailing startup unveiled a new device on Thursday called Uber Beacon, which can be placed under the driver's windshield. Its purpose is to identify the car by flashing a designated color.

When you hail an Uber, you can select from a wide variety of colors within the app. Your car will then display an Uber logo lit up with that same color, making it easier to pick out in a crowded place or at night.

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The device will begin rolling out to drivers this week in Miami, Denver, Nashville and Newcastle in the U.K., with plans for more cities to follow in 2017.

Uber Beacon is similar to Lyft's Amp, a device unveiled last month that flashes a certain color from the dashboard.

"When it's nighttime and dark, and you're squinting at a car, from a security perspective that's not great," said Ethan Eyler, head of ride experience at Lyft. "Now you don't have confusion of walking up to the wrong car, or getting in the wrong car."