Microsoft surprised us all with the Surface Duo this week. It’s the long-awaited Surface phone that has been rumored for years, and in a further surprise, it’s running Google’s Android operating system. It’s designed to be the smaller sibling to the Surface Neo, a dual-screen device that was also unveiled yesterday running Windows 10X.

The Surface Duo has two 5.6-inch displays that fold out into an 8.3-inch overall screen, and it’s just 4.8mm thin. You can fold it fully over like many 2-in-1 laptops, thanks to a 360-degree hinge. Microsoft says it’s committed to dual-screen devices because they allow people to get more done on the go.

I got a chance to take a closer look at the Surface Duo this week, and my first impression was simple: it’s so much smaller in person than it appears in photos. I wasn’t allowed to play around with the software on this device, but I was able to slip it into my jeans pocket, and it’s definitely the first pocketable Surface device. It looks and feels like a miniature tablet that’s also a phone.

Microsoft doesn’t consider this a phone, though. “I feel like ‘phone’ is such a limiting word,” says Microsoft chief product officer Panos Panay. “And then you say, ‘well, smartphone.’ I don’t even know what that means. And then ‘phablet.’ I’m not sure what that is. I think if you’re going to create a new category, you’re going to try to change things, push things forward. The minute you put it in a box, I think you’re lost. So I’ve been pretty resistant to that. Not because it doesn’t act like a great phone.”

Phone or tablet debate aside, the hardware isn’t really the star of the show. It’s extremely surprising to see Microsoft launch both Android- and Windows-powered devices that are dual-screen and share the same design. Microsoft is using Android on the Surface Duo, which might sound surprising, but it’s realistically the company’s only choice if it wants to build a pocket-sized device that can replace your phone.

Panay admits that’s precisely why the Surface Duo runs Android. “Well, because those are the apps you want,” says Panay. “Because there’s hundreds of thousands of apps, and you want them. And [Microsoft CEO Satya Nadella] and I talked about it, and it’s about meeting our customers where they are, where they’re going to be. I don’t think the mobile application platform’s going anywhere anytime soon.”

“It’s pretty simple. Like, literally, you need the apps.”

He’s not wrong. Microsoft tried and failed to capture developer and consumer attention with Windows Phone, and it just couldn’t get the market share needed to compete with the dominance of iOS and Android. So it’s embracing Android fully with its own Surface hardware, just like it has been gradually embracing Android as the mobile equivalent of Windows in recent years.

The decision will trigger a number of questions around the future of Windows, Microsoft’s efforts with Android, and much more. Microsoft has partnered with Google for dual-screen devices, and the company appears to want to create some type of API layer on top of Android. That will require deep integration, and it means Microsoft is contributing code to Android as well. That could mean Microsoft’s future, like its work on Chromium, is built on Google’s code, but Panay doesn’t see it that way.

“No, no, no, no, no, no, no, no,” says Panay in response to the possibility of Android being the future for Microsoft. “You want to give customers what they want in the form factor that they’re using. We’ve learned this — let’s put the right operating system on the wrong product or the other way around. But what’s the right operating system for the form factor? And in this case, on mobile devices, Android’s the obvious choice, But anything [bigger than] that, Windows is everything.”

Panay says Microsoft has been working on the Surface Duo hardware for three years, so this isn’t an immediate reaction to Samsung’s Galaxy Fold, Huawei’s Mate X, or anything else. The company has opted for two separate glass displays instead of folding plastic, and it’s clear Microsoft thinks this is the way forward until foldable display technology is really ready. Panay says the hardware won’t change between now and when the device launches, although there’s a Snapdragon 855 processor inside right now that could be upgraded to Qualcomm’s latest next year. There’s also no camera on the outside of the device, and the idea is that you use the one included above the display to shoot pictures by flipping the display over.

So what exactly does Android on the Surface Duo give you that a regular smartphone isn’t capable of? Microsoft showed off some examples of dragging and dropping content between apps and displays on the Duo, and Panay hints that the company could use Project xCloud to have a game running on one side and a controller on the other. But it’s really early for the software side of things, and Microsoft hasn’t figured out every scenario just yet.

But that’s why the company announced the Surface Duo and Surface Neo a year before they’ll ship. Microsoft needs developers to support its dual-screen ambitions, and it wants to get the Surface Duo and Neo devices out there so that apps can be created for when they arrive in late 2020. “I don’t know if we did the right thing or wrong thing, but we do want to inspire developers,” says Panay. But what he will say is that “The hardware won’t change at all,” between now and when the device ships next year.

The real question is: what happens when devices the size of this Surface Duo are capable of supporting screen sizes as big as the Surface Neo and beyond? A smartphone that converts into a tablet, a laptop, and even a full PC with a dock has long been the sci-fi dream of the future, and it’s entirely possible we’ll get a device that attempts this in the next decade. What if a Surface Duo running Android is so successful that Microsoft wants to make a slightly larger one that runs up against the Surface Neo running Windows 10X?

“I don’t see that,” says Panay. “Anything bigger in between Neo and Duo, I think, is stuck.” Microsoft has spent years looking at different screen sizes, with considerable amounts of research backing its decisions. “Eventually we got to, ‘What are people going to do? What’s the right size? And what’s the biggest we can make it but still make it as small as it can be?’ And I know that sounds like a kind of oxymoron, but that was the push. We found the design point of where I think the largest product can be in the mobile space. That’s what I believe. And so I could be wrong, but I also look at my road map, and we’re not looking at anything bigger than this. We found the design point of where I think the largest product can be in the mobile space.”

So that leaves the question of when it will ship, and what the pricing will be. Pressed on ship dates, Panay says “we’ve got probably a couple more months [before developers are] going to have their hands on it and be running,” but he won’t talk about pricing at all except to say people will be “super happy,” clarifying that “when I say happy, I think the value of the product you get for how much you’re paying, it’s there, and that’s what matters to customers.”

Microsoft announced a lot of new hardware this week, and it’s starting to feel like the company has a Surface device for nearly everyone. There’s now a Surface Duo phone that does slightly more than a regular smartphone, with an extra display thrown in, and a Surface Neo or Surface Pro if you want to go from a tablet-like device to a laptop. There are giant displays like the Surface Hub 2, or unique all-in-one PCs like the Surface Studio. Microsoft is even covering the bases of accessories with its Surface Headphones and Surface Earbuds.

Surface started out as a futuristic table before Microsoft launched its tablet and laptop hybrid, and it’s now so much more. It’s Microsoft trying to be innovative, chasing what it thinks will be the next major hardware form factor shift and trying to have a software and developer ecosystem in place when it goes mainstream.

Microsoft will now need to convince app developers and consumers that these dual-screen devices are truly the new device category we’ve all been waiting for. However things end up, Surface is no longer just a tablet that’s also a laptop. It’s Microsoft’s idea of the future.

Update: Added quotes from Panos Panay on pricing and ship date, and noting that the hardware won’t change.