Late last month, HTC started its rollout of Android 5.1 for HTC One M9 users, using the T-Mobile-specific version of the phone. It bumped the software version up to 2.7.531.6, and included Lollipop’s new anti-theft features, battery improvements, and other miscellaneous changes under the hood.

Now, HTC has made the official RUU available for download, as well. This won’t affect most normal users, but RUU files are important for people who do a lot of tinkering on their phones, and want a relatively fast and easy way to return their phones to a completely stock state. In other words, it’s kind of like the Nexus factory images, but with a slightly more refined user interface – and only for HTC devices.

To download the RUU to your computer, simply visit the source link below and scroll¬†alllllllll¬†the way down to the very bottom. And you’ll definitely want to do it from a wired connection if your mobile data plan isn’t unlimited – this sucker is 2.15GB.