The often-troubled Taiwanese smartphone manufacturer HTC has managed to generate a lot of buzz for its upcoming late-release handset, in large part because it is slated to be one of the first non-Nexus devices to run the newly released, and still rare, Android 6.0 Marshmallow right out of the box.

On Oct. 20, HTC will unveil the mysterious new smartphone at an all-digital event the company is dubbing #BeBrilliant. Here's what we know about the new Marshmallow phone from HTC.

Rumors have swarmed around this handset since mid-summer, and with the benefit of hindsight, we can see which leaked specs, features, and other details look most likely to be correct.

For one, the device is almost certainly going to be called the HTC One A9, as the earlier moniker "Aero" appears just to be HTC's internal code name, according to CNET.

Also, the earlier rumors about the phone's specs appear to be pretty off base. As PhoneArena pointed out, some of the first leaks and rumors surrounding the "Aero" had up to 4GB of RAM, a deca-core system on a chip, and a hefty price tag. But later leaks by reliable sources have pinned the HTC One A9 as more of a mid-tier device.

Consensus seems to be forming around either a Qualcomm Snapdragon 617 with 2GB of RAM or, according to AnTuTu benchmark leaked to Weibo, a Snapdragon 620 with 3GB of RAM. Either way, it's not looking like a new flagship that's replacing the HTC One M-series, the most recent of which was only released earlier this year.

Along with the consensus of a reasonably powerful mid-range Snapdragon SoC, rumors about the display are indicating it's going to be a solid, but not exciting, 5-inch touchscreen with 1080p resolution.

In addition, some leaks have the HTC One A9 being the thinnest-ever HTC phone, and some support the notion that the device will come with a fingerprint scanner just below the home button. We'll just have to wait to see if those are confirmed or not.

One thing that's certain, and HTC is letting everyone know about it, is that whatever smartphone the company unveils on Oct. 20 looks like, it'll be the first new OEM device running Android 6.0 Marshmallow built-in.