Apple spent much of its September 12 special event talking about its three new iPhone models. However, it was the preceding Apple Watch Series 4 announcement that really captured our attention.

This is arguably the biggest upgrade to the pioneering smartwatch since it first hit the market in 2015. Here’s what Apple had to tell us.

Bigger screen, new body

While it still looks quite familiar, the Apple Watch Series 4 actually represents the first big redesign since it launched. It now has a larger display that stretches closer to the edges of the device, with a corresponding increase to the fonts and app icons of watchOS 5.

Depending on which of the two models you pick, you’ll get a 32 or 35 percent increase in screen size over the previous models. Those displays will pack in 30 percent more pixels, too.

The Apple Watch chassis has gotten a tiny bit bigger in the process, but it’s also thinner than before. As a result, it actually has a lower total volume than the Series 3.

Fresh faces

To show off those big, sharp new displays, Apple is bringing a bunch of new faces to the Series 4.

The headline addition is a new Utility face that crams in up to eight different complications. Despite this, it doesn’t look too cluttered courtesy of that expanded canvas.

Elsewhere you’ll find strikingly animated Fire, Water, and Vapour dials, as well as a stress-busting Breathe design.

Faster S4 chip

We expect Apple’s products to get faster with every iteration, but the new S4 chip that powers the Series 4 looks to be a major leap forward.

The S4 incorporates a dual-core 64-bit CPU, which is an estimated two times faster than the chip in the Series 3.

Radically revamped Digital Crown

Apple has completely re-engineered the Digital Crown on the side of the Apple Watch Series 4. It now produces haptic feedback, which means it’ll provide subtle tactile feedback as you rotate and press it.

More outlandish is a new sensor contained within the Digital Crown that will give you a bona fide, FDA-approved electrocardiogram (ECG) test. Open the relevant app and push your finger up against the Crown, and 30 seconds later your S4 will have provided an accurate recording of your heart rhythm. This is a world first for consumer-facing tech.

The ECG functionality will be US-only at launch, but Apple says it’s working on expanding it around the world.

Mind the step

Not only will the Series 4 be able to monitor your heart, but it’ll also know when you take a nasty fall. Using a new and improved accelerometer and gyroscope combo, in conjunction with that advanced S4 chip, the latest Apple Watch will be able to detect a bad fall and bring up an emergency call prompt.

If you don’t move for a minute, the Apple Watch will then make the call for you, as well as sending alerts to your emergency contacts.

Better calls

Apple clearly wants you to talk to people on your Apple Watch, Dick Tracy style. To that end, it’s made the Series 4 speakers 50 percent louder than before.

The company has also shifted the mic to the other side of the watch. In other words, as far away from those bolstered speakers as possible for minimal call disruption and echo.

Finally, Apple has made the Series 4 out of black ceramic and sapphire crystal to help give it better cellular reception. The combined effect should result in clearer calls, Siri requests, and Walkie Talkie jibber-jabber.

No boost to battery life

Those looking for more stamina from Apple’s smartwatch will be a little disappointed. The Apple Watch Series 4 will last only as long as the Series 3 before it – around 18 hours of use on a full charge.

Given the advances Apple has made with the Apple Watch Series 4 elsewhere, though, we reckon that’s actually quite an achievement.

Pricing and availability

Pricing for the Apple Watch Series 4 starts from $399/£399 for the GPS model and $499/£499 for the GPS + Cellular model, while the Series 3 gets a price cut.

Pre-orders are now open in the US, UK, Australia, and other selected countries, with availability from September 21.