This is the year of the smart ring. Samsung released the Galaxy Ring a few months ago and we found it a little underwhelming, but Samsung's main smart ring rival is so far down the line that it has just announced its fourth iteration. The Oura Ring 4 from Finnish company Ōura replaces the Oura Ring 3 that debuted in 2020. Compared to that device, the new model is fully round and its sensors inside are flat rather than three protruding bumps.

It will also prove to be a main smart ring rival to the recently-released Samsung Galaxy Ring, which has many of the same features but is more of an accessory to Galaxy phones and watches than a standalone health tracking device.

All colours of the Oura Ring 4 are made from titanium, with six colours to choose from and in ring sizes 4 to 15. If you’re not sure what size you are, when you buy the ring Ōura will send you a free sizing kit with all sizes in plastic rings to try on so you can decide.

The Ring 4 includes heart rate, blood oxygen and skin temperature sensors to collect 24/7 health and fitness data. The ring pairs to your iPhone or Android phone and you can view all the health data it collects via the app.

“Oura Ring 4 is built around a breakthrough sensing technology, Smart Sensing, which is powered by an algorithm that works with research-grade sensors to dynamically adapt to the finger and deliver accurate and continuous data, day and night,” Ōura said in a press release.

Smart Sensing is exclusive to the Oura Ring 4 and combines the firm’s algorithm alongside the new ring’s improved sensors to bring what Ōura claims is “an unparalleled degree of accuracy, comfort, and personalisation”. Honestly, we are just hoping the ring is more comfortable and, well, smarter.

When wearing the Oura Ring 3, we found it was a little too thick to forget it was there, unlike regular rings or wedding bands. You’re also meant to wear these devices on your index finger, which can be uncomfortable when the ring is so thick.

Ōura says the Ring 4’s sensors have 18 "signal pathways" compared to just eight on the Ring 3. This could be key in seeing an improvement in data readings as well as wearer comfort. Not only are the sensors now flat, there are more of them, so you don’t have to necessarily ensure the ring is in the correct position to get good readings.

With the Oura Ring 3, you had to make sure the sensors were on the underside of your finger, marked on the outside of the ring with a small divot. The Ring 4 can twist and turn throughout the day like you’d expect when wearing a ring, and allegedly your data accuracy won’t suffer for it.

The new Smart Sensing tech is said to “automatically adapt to find the best signal path, ensuring continuous, accurate data in any situation, all while optimising the battery to achieve up to eight days of battery life”.

Though it’s designed to be worn all the time, the ring needs charging every few days, which is done by placing it on a small USB-C powered charging nub.

The companion app has been updated to better show you your health data as well as provide timely tips on what you could be doing to get better sleep, or let you know if you may be getting ill. The ring can also help you track your menstrual cycle.

Available from 15 October exclusively from John Lewis in the UK, the Oura Ring 4 will cost from £349, with some colour finishes costing more. One catch is that for full data access and all possible features you need to pay a subscription fee of £5.99 per month or £69.99 annually. Samsung does not charge a subscription fee for its £399 Galaxy Ring, but it offers different features.