Apple Watch Series 6 is the best smartwatch for iPhone users and, by now, that shouldn’t come as a surprise. The Apple Watch Series 5 before it—and the Series 4 before that—were both great and Series 6 hasn’t changed all that much. And while tech bloggers and industry analysts typically balk at granular generational improvements, Apple’s wrist-worn computer has no need to worry about its status as the world’s most popular watch. The company clearly didn’t think the Apple Watch was broken and had no intention of trying to fix it. 

While Apple Watch Series 6 (starting at $399 for an aluminum case and GPS without cellular connectivity) isn’t profoundly different from previous models, it does offer a few notable upgrades and features that give it an edge over its older siblings—as well as its newly arrived little friend, the Apple Watch SE.

What’s new in Apple Watch Series 6?

Many of the new hardware features found in the Apple Watch 6 feel like they’re laying the groundwork for the future. That’s a common theme with Apple’s flagship products: Consider the LiDAR sensor inside its iPad Pro, which has some limited use for pros now, but will only become more useful over time. Some of the new Apple Watch features have that same vibe. Here’s an overview of the most notable new stuff you’ll find inside.

Blood oxygen sensor

Flip over the case and you’ll find that the Apple Watch 6 features an entirely new blood oxygen sensor nestled in with the infrared heart monitor. The hardware attempts to read the oxygen saturation in your blood. It emulates the little finger clamp device hospital staff use when taking your vitals. For patients with breathing issues or illnesses, it can be a useful metric. In the Apple Watch’s case, however, it’s only meant as a wellness tool for tracking overall health.

When the sensor is working, it emits bright illumination from its LED array so it can measure the light reflected back to get a reading. You can trigger a reading manually, but the device will also monitor this stat in the background. It’s goal is to observe long-term trends more than up-to-the-minute levels. 

The sensor is clever, but finicky. During a manual reading, my results typically made sense, falling around 98 or 99—anything between 95 and 100 is normal. To do it right, however, you have to make sure the Watch is positioned farther up your arm I usually wear it. You also need to stay still for the 15-second reading. Because background sensing doesn’t typically enjoy these idyllic settings, I found them somewhat sporadic. Every once in a while, I’d get a value that would suggest I should be dead. As a gadget writer, I know it’s fine, but as a hypochondriac, it hurt a little. 

Brighter always-on screen

Starting with Apple Watch 5, the wearables’ OLED screens stayed at least somewhat illuminated when you weren’t looking directly at them. That makes it possible to catch a glance at the time or your notifications without making a conspicuous arm gesture. In Apple Watch 6, the always-on display is now 2.5 times brighter in ambient mode. That makes it much easier to see, especially in bright conditions. 

Despite the extra screen brightness, the Apple Watch 6 still promises the same 18-hour Apple Watch battery life as its predecessor. I’d guess it has a lot to do with improved performance when it comes to the screen’s variable refresh rate. If the image changes less often, that can make up for the power consumed by the extra brightness. This feature is handy and I hope the next model pushes it even more.

U1 chip

When Apple announced the U1 chip inside the Apple Watch 6, the hardware didn’t actually do very much. It stayed that way for several months. Now, with the impending release of watchOS 8, we’re finally starting to see its potential. 

The U1 chip is a short-range wireless chip that can sync to other compatible devices with a super-fast connection that can help hone in on hyper-specific locations. In the upcoming watchOS 8 release, Watch will get its own version of the FindMy app. You’ll be able to use it to track down AirPods, iPhones, or AirTags right from your wrist. 

Apple has also promised that its U1-equiipped devices will soon work as full-fledged keys for cars and even smart locks. Right now, these functions are super-limited, so they won’t come in handy right away, but at least we have an idea of how Apple intends to use the U1 down the road.