The third phase of Android Q is now available to download and install on your Pixel device, as well as on 15 other devices. The latest update brings a few new features in tow, including an oft-requested Dark Theme, some new gesture controls, and other changes that you can read about in Dieter Bohn’s exclusive look at the major Android update.

Since this is a beta intended primarily for developers, you might want to think twice before installing it on your personal phone. Past beta phases for Android 8 Oreo and Android 9 Pie eventually became fairly stable for day-to-day tasks, but only after a few months of availability.

If you want to download the new software, you’ll need one of 21 phones. Previously, support for Android Q was limited to the original Pixel, Pixel XL, Pixel 2, and Pixel 2 XL, Pixel 3, and Pixel 3 XL. The full list of phones that can run the beta has grown to 21, including 15 new devices:

Asus Zenfone 5Z

Essential PH-1

HMD Global Nokia 8.1

Huawei Mate 20 Pro

LG G8 ThinQ

OnePlus 6T

Oppo Reno

Realme 3 Pro

Sony Xperia XZ3

Tecno Spark 3 Pro

Vivo X27

Vivo NEX S

Vivo NEX A

Xiaomi Mi Mix 3 5G

Xiaomi Mi 9

The installation process for the new operating system is pretty easy, but if you run into issues that have you wanting to run back to a more stable version of Android 9 Pie, you’ll have to completely reformat your phone.

The instructions below are written with Pixel phones in mind, so the process to install the software (and the arrangement of menus) may differ a bit depending on the phone that you’re using. Here’s how to get the latest (and currently unfinished) Android software on your phone.

Back up your device

It’s super important to make sure that your data is backed up. Before you get started, open up your settings, navigate to “System,” and once you click through, hit “Backup.” This screen will tell you if your phone is set to back up its data. If the setting is on, it does a good job of informing you when you last backed up your phone’s most important stuff to your Google Drive. If this feature isn’t activated, turn it on.

The initial backup might take a while, but if things go wrong with Android Q, you’ll be happy that your data (including apps, SMS texts, photos and videos, call history, and more) is ready for you to download should you need to reinstall Android 9 Pie. Google notes that, even when you back up your data, errors can still occur when downgrading your software, so don’t be surprised if things don’t feel exactly as you left them.

Enroll in the beta

If you’re not the kind of person who wants to unlock your phone’s bootloader, I can’t blame you. Google lets Pixel owners enroll in the beta by simply logging in with a Google account, then selecting the compatible device on which they’d like to install the beta. You’ll get an over-the-air update that way, just like you normally would for stable versions of Android.

Once you click “Enroll,” you’ll eventually get an update notification on the enrolled device that a system update is ready. You may need to check for a system update in order for it to fetch the beta software, but it usually doesn’t take long for it to be ready for download. (Google says it could take 24 hours or more, but we’ve rarely had to wait that long. The beta hit one of our phones less than a half-hour after enrolling it.)

As new Android Q developer previews come out, you’ll get a notification to install them, too, as you would for any regular system update.

Alternatively, you can flash the Android Q beta to your Pixel phone. Google has provided a list of image downloads for the supported phones, but you should only take this road if you’re a developer, or if you just like to do things the hard way. Phones that are updated in this manner won’t receive over-the-air updates to upcoming beta versions, so if you want the latest Android Q features without much hassle, just enroll in the beta instead.