Matthew Miller/ZDNETWhat's the deal?The Amazfit Helio Ring is on sale for $170 (save $30) during Amazon's Presidents' Day sale. That's 15% off on Amazfit's flagship smart ring.ZDNET's key takeawaysThe Amazfit Helio Ring is available now in two sizes for $299.99.It's comfortable, attractive, and syncs with Amazfit smart watches.The battery life only lasts four days, the Zepp smartphone software is confusing, and active heart rate readings were inaccurate in my testing.As a fan of smart watches, I wear one on each wrist on a daily basis. But I don't like wearing watches to bed, as they get tangled in the sheets and light up when you're trying to fall sleep. This has left me without a way to track sleep metrics, until I started using smart rings.Also:The best smart rings you can buy: Expert testedI tested the Oura Ring a few years ago, and I found that it was the best device for me to capture sleep and health data because of its unobtrusive form factor. The problem is that Oura's sleep data doesn't interface with my sports watch, requiring me to run two different apps to get the full picture of sleep and health data.So when I met the folks at Amazfit at CES in January, I was excited to see their plans to integrate theHelio Ring into the Zepp ecosystem along with the data from the Amazfit smartwatches. Could this be the complete solution for understanding your health and wellness? details View at Amazfit I spent about 10 days with the new Amazfit Helio Ring, along with the Amazfit Cheetah Pro Kelvin Kiptum Commemorative Edition smart watch to find out. The Amazfit Helio Ring is available for $299.99 in sizes 10 and 12, although more sizes will launch in the future. The ring's sole available color is called titanium, even though it has a warm, slightly bronze tint to it.Also:The best smart ring for fitness junkies beats the Oura in 4 major waysI tested the size 12 titanium alloy ring, which weighs just 3.82 grams, with an 8mm width and 2.6mm thickness. It is completely round, with no flat spots, unlike other smart rings. The ring also has a 10 ATM grade for water resistance and is powered by a 20.5 mAh battery with a wireless ring charging dock very similar to the same method used by other smart rings.The ring includes a PPG heart rate sensor, 3-axis accelerometer, 3-axis gyroscope, temperature sensor, and EDA sensor, so there is a lot of technology packed into this small wearable device. Amazfit advertises up to five days of battery life, but in my testing I'm seeing about 25% battery consumption per day. For comparison, I typically charge the Oura Ring about once per week, so the battery life is a bit lower on this device.The Helio Ring and an Amazfit watch both sync to the Zepp smartphone application, which employs its built-in algorithms to provide the appropriate health data. Wearing just the ring to sleep, as designed, reveals a readiness score, sleep score, sleep resting heart rate, sleep heart rate variability (HRV), and recovery time. A further breakdown of your sleep, including time and percent in deep and REM sleep, appear on the sleep tab of the Zepp app. Matthew Miller/ZDNETThe app is powerful, but it's not the most intuitive, with an overabundance of settings, customization options, and data views that can result in spending too much time trying to find what you're looking for. I've found there are multiple ways to access your data, it just might take some time to discover which way is best for you.Also:Why I wear this $220 smartwatch even after testing Garmin and Apple watchesWhile wearing multiple devices all at once to compare, I found the Helio Ring matched the Oura Ring and Polar watch closely with sleep score, sleep duration metrics, and HRV. However, the time in each sleep stage, resting heart rate (RHR), and readiness scores ended up looking quite different.I compared the RHR to the watches, and found that the Oura Ring closely matched them, while the Helio Ring was the outlier, showing an average of 10 bpm more than the other devices. This is a significant difference when my standard sleeping average heart rate hovers around 40-42 bpm. Matthew Miller/ZDNETThe readiness score is probably the most important metric since many people use that to help inform them of their fitness plans for the day ahead. But with the Helio Ring showing significantly lower scores, a person may avoid activity when their body is actually ready for more. Upon investigating this, I couldn't determine any obvious reason why the Helio Ring skewed lower for readiness scores.In order to view weekly or monthly reports, readiness insights, or Zepp AI Coach details, various subscriptions are required. While there is no subscription required to use the Helio Ring and view basic details, one is required to access all of the data captured by the ring. Matthew Miller/ZDNETAdditionally, during my testing of the Helio Ring, it showed a resting heart rate nearly twice as high as shown by the two watches and the Oura Ring. Regarding exercise data, the Helio Ring also provided some pretty different results than my other devices, leading me to believe that the Helio Ring is best used as a sleep tracker, which, luckily for me, was my goal all along. Also: The best Apple Watches of 2024: Expert tested and reviewedThe potential to have a smart ring and watch work together for a consolidated health and wellness experience is there, but the current experience with the Amazfit Helio Ring provided some inaccurate data that didn't quite meet my expectations. Perhaps additional software enhancements will address these data metrics.ZDNET's buying adviceSmart rings are becoming a very popular accessory for discretely tracking your health and wellness data, particularly for sleep since wearing a watch to bed isn't everyone's cup of tea. The current challenge, however, is integrating the smart ring's data with that captured by a sports watch. Amazfit's Helio Ring has the potential to solve that challenge, but work remains on the Zepp software and reliability of the heart rate data.The RingConn smart ring is another option I previously reviewed if you're looking for a smart ring suitable for fitness metrics. The Oura smart ring, however, is one of the best on the market right now.Featured reviews