Today’s big tech news might be the fancy-looking Surface Studio PC, but Microsoft also decided to make a major virtual reality announcement during its Windows event: a whole new line of VR headsets with built-in tracking sensors, starting at the surprisingly low price of $299.

Manufactured by Microsoft partners like Asus, Acer, Lenovo, HP, and Dell, the headsets were shown briefly, and in little detail. But we saw just enough to raise a lot of questions about how they’ll actually work — and what they’ll mean for virtual reality.

We’re partnering with top PC makers to build a range of innovative VR headsets starting at $299. Coming in 2017. #MicrosoftEvent pic.twitter.com/pMnFbJFZe6 — Windows (@Windows) October 26, 2016

What is inside-out, six-degree of freedom tracking, and why is it a big deal?

The major selling point of Microsoft’s new line of devices is what’s known as inside-out, six degree-of-freedom tracking — and if they pull it off, it could mark a legitimate breakthrough for virtual reality. Six degrees of freedom refers to motion tracking that can tell when you’re moving through space, not just turning your head. Right now, it’s the key difference between a high-end headset like the Oculus Rift, and a mid-range or cheap one like the Gear VR or Google Cardboard.

But in order to enable 6DOF, systems like the Rift require an external tracking system that makes the whole setup more complicated and less portable. This is where inside-out tracking comes in. Instead of having an external camera read the position of LEDs on your head (which is how the Rift works), sensors built directly into the headset will detect how the wearer is moving and adjust their in-VR position to match. As Microsoft executive VP Terry Myerson puts it, this means people would have “zero need” for a dedicated VR room — they’d just put the headset on and start moving around.

How is this different from HoloLens?

HoloLens is an augmented (Microsoft prefers “mixed”) reality headset, which inserts holograms into reality. Virtual reality headsets totally overwrite your view of the world, using magnifying lenses and a flat screen to project an image around your entire field of vision. You can load the same 3D objects in both, but a VR headset will display it in a completely virtual environment, while HoloLens will project it on top of whatever you’re already looking at.

That said, there are some significant similarities, including the fact that HoloLens uses inside-out tracking to pin its holograms in place — and in fact, Myerson tells us that the headsets will be “leveraging all kinds of HoloLens technologies.”

How much will you actually be able to move?

This is a serious, and unsettled, question. The ultimate promise of inside-out tracking is that you can pretty much create the Holodeck: as long as you have physical space to move, the headset will be able to tell where you’re going. But that requires hardware and software that can track location accurately over long distances. HoloLens lets people move around entire rooms, but the consequences for a hologram drifting a little (which, in my experience, does happen) are a lot less severe than having your entire world slip out of place.

In today’s demo, nobody moved more than a couple of steps, going from one end of a closet-sized room to another. Even this would be a marked improvement over non-positionally tracked headsets like the Gear VR, because being in a world that doesn’t react to your motion at all can be jarring or even nauseating. But it’s not equivalent to the experience you’d get in most high-end VR headsets.

What kind of computer will this require?

From what we’ve seen so far, the headset also isn’t self-contained like HoloLens; it’s wired to a Windows 10 computer of some sort. Myerson knocked the Rift and Vive for requiring expensive PCs, and a press image showed the headset alongside what looks like a Lenovo Yoga laptop, not a supercharged gaming machine. This would make it a more accessible device, although it could also mean its graphical capabilities are limited.

On the flip side, it’s worth noting that HP and Dell are both working on powerful VR backpacks, through their respective Omen and Alienware gaming brands. Right now, they effectively only support the HTC Vive, but they’d also be a perfect fit for the headsets Microsoft is describing.

How will you interact with the headsets?

Controllers are a bigger and bigger part of the virtual reality equation. HTC has its trusty remotes, PlayStation VR uses the aging Move controllers, Oculus’ Touch controllers are coming out in December, and Google designed a simple remote for its newly announced Daydream headset.

Microsoft hasn’t shown us a dedicated physical controller, and on stage, people seemed to interact with the headset via voice command, like HoloLens. If Microsoft’s partners are using HoloLens camera tech, we could see them adopt the “air tap” hand gesture as well. This is far from the most robust interface out there, but it neatly solves the basic problem of interactivity without requiring any new hardware. For more complicated interactions, people could turn to mice, keyboards, gamepads, and other existing systems.

Where was Oculus?

A year ago, Microsoft and Oculus seemed to have a tight relationship: Oculus shipped its headset with an Xbox One gamepad, and Microsoft announced that you’d be able to play Xbox games on your Rift. But that latter promise still hasn’t panned out, and neither Oculus nor the Rift apparently merited a shout-out at today’s event. In fact, Myerson implicitly trashed the headset as “less immersive” than Microsoft’s new lineup.

You could argue that this is because Microsoft is treating inside-out VR as a totally separate category from the Rift and Vive (which is also sold through the Microsoft Store, but wasn’t mentioned today.) But there’s still one odd wrinkle: Oculus announced its own inside-out headset, called the Santa Cruz prototype, just a few weeks ago. It’s not quite the same as what Microsoft showed off; for one thing, it’s totally self-contained, not tethered to a laptop. But if there was ever a time for the two companies to work together, this was it — and Oculus was nowhere to be seen.

When will these come out, and how much exactly will they cost?

We still don’t know what individual Microsoft partners’ headsets will look like or be named. Microsoft says that they’ll be coming in 2017, and they’re described as part of the Windows 10 Creators Update, a big 3D-focused upgrade to the operating system. If they’re released exactly at launch, which is by no means a given, that narrows it down to next spring. Microsoft is supposed to be providing more details soon at the WinHec conference in Shenzhen, China.

As for pricing, the headsets “start” at $299, compared to the $399 PlayStation VR, $599 Oculus Rift, and $799 HTC Vive. But we don’t know the upper price range, or how much the price will vary based on manufacturer and specifications. Myerson tells us that “some of those headsets being worked on are just fantastic, and won't be at lower price points, but some will be at these low price points.”

Microsoft has promised something that doesn’t yet exist in mainstream VR, at a price that’s potentially very unusual. Almost every major VR headset release so far has slipped by several months at least, and prices have often ended up higher than people expected. So until we have firm launch details, you should consider these headsets next-generation products, not just-around-the-corner competitors to the Rift or Vive. That said, they’re certainly an exciting idea — and we’ll be eagerly awaiting more news from Microsoft’s partners.

Microsoft's Wednesday event recapped