At one point, Apple’s wearables group was its fastest-growing division, with many hopes and dreams pinned on it. Apple’s famous head designer, Jony Ive, saw the Watch as their gateway to fashion, launching it at Paris Fashion Week and selling a $17,000 pure-gold version. Others inside Apple saw it as key to their future of connected, dispersed computing, envisioning the Watch as the key to an Apple car, an authentication device for all your devices, and a core part of their “spatial computing” virtual reality headsets. The reality, however, is that people use the Apple Watch the same way they’ve used other wearables — as a health tracker. The market has long reached saturation. What was expected to be a high-growth division has become one of Apple’s slowest, which is why the new, revamped Series 10 Apple Watch is so important for the company.

To be clear, the changes are small. There are no revolutionary new features, nor does it play with shape and size the way the Ultra line does — it’s still quite similar to the Series 1 Watch. It’s an Apple Watch Series 9 but with a thinner body and a significantly bigger screen. Unlike the new iPhone, though, these small upgrades are fairly meaningful.

To start, the screens. The Series 10 has the largest and “most advanced” screen they’ve ever put on a wearable, making it slightly bigger than even the Watch Ultra 2, in a 9.7mm thin body. This is a wide-angle OLED display, which — in combination with its increased brightness — will apparently make it easier to read from various angles.

The hardware has a few other updates. It comes with a faster S10 chip and a reengineered speaker, which is smaller but just as effective and now lets you play media through it. You shouldn’t, though. More importantly, the bigger charging coil means you can get 80 percent charge in just half an hour, which is fantastic.

Health tracking has also been upgraded. The Series 10 includes swimming-centric features — a depth gauge and water temperature sensor, along with a new Tides app — and long-awaited sleep apnea detection. In Europe, this isn’t particularly novel, as it’s available on many wearables and sleep-tracking devices. However, it’s hard to get past U.S. regulators, and therefore generally removed from the U.S. versions. Apple hasn’t received FDA clearance yet, but expects to soon, so those who sleep with an Apple Watch will be happy. This feature will also eventually be available on the Series 9 and Ultra 2.

It’s worth noting that it doesn’t come with blood pressure sensing, as initially anticipated. According to Mark Gurman of Bloomberg, this feature has been delayed and won’t arrive until Series 11. Additionally, no new Apple Watches have blood-oxygen sensing, which was removed after a lawsuit earlier this year. If you value that feature and have a 2023 or earlier Apple Watch, you might want to hold off upgrading for now.

The Series 10 comes in the classic silver and rose gold colors for the aluminum version, along with a new jet black polished aluminum, which looks beautiful. You can also get the watch in titanium, which replaces the steel version, in “natural,” gold, and dark slate grey. It’s 20 percent lighter than the steel watches, which seems cool, though many might miss the heft of steel.

The Series 10 starts at $399 for Wi-Fi only, and $499 for the cellular model.

Then there’s the Apple Watch Ultra. Though a Series 3 version of the Ultra is currently in development, it wasn’t released here, so those looking to buy Apple’s best watch, with the biggest screen and longest battery life, will have to settle for the current Watch Ultra Series 2. However, it’s now available in satin black. Oooh. This might seem minor, but the blacked-out finish, along with the titanium Milanese loop band with a rollercoaster buckle, similar to belts from the fashion brand Alyx, will sell ridiculously well. People with too much money, who already own a Watch Ultra, will likely buy another just for the new color.