Circular’s upgraded Ring Slim is here to take on the Samsung Galaxy Ring

Summary

• Circular’s new Ring Slim (2024) is the world’s thinnest and lightest smart ring, offering improved battery life and build quality.
• The upgraded health-tracking capabilities include a new sleep algorithm and accurate heart rate monitoring during sports activities.
• The Ring Slim (2024) comes with the Kira+ app for tracking and analyzing health data, and there are no monthly subscription fees.

The smart ring category is still in its nascent stage, but it is bound to see a lot of action in the coming months and years. Oura is currently the biggest player in this segment, with smaller players like Ultrahuman and Circular also trying to take a piece of the market with their offerings. Now, in a bid to steal the spotlight and a bit of the thunder of Samsung’s upcoming Galaxy Ring, Circular has launched the 2024 variant of its Ring Slim with new health-tracking features.

Circular’s last smart ring, the Ring Slim, arrived in November 2023—three years after the Pro 1, its first wearable — with a slimmer and lighter body. The original Ring Slim was criticized for its poor battery life, sub-par app experience, and inaccurate data tracking. Seven months later, Circular is launching the 2024 model, addressing all the problems that plagued its predecessor.

The Ring Slim physically looks the same as its predecessor, but it now carries an IP68 certification for dust and water resistance. Additionally, the scratch-resistant coating is better than before, so the wearable should show fewer scuffs and scratches.

The charging pins are also smaller and rounded, ensuring they hold the ring in place on your finger. More importantly, Circular is now bundling a compact USB-C charger with the Ring Slim, so you can charge the wearable directly from your phone if you wish to.

Despite these build quality improvements, Circular claims the Ring Slim is the world’s thinnest (2.2mm) and lightest wearable (2 grams) in the world. In Performance mode, the Ring Slim can last a claimed 2 days, while Eco mode boosts its runtime to 5–6 days.

Circular Ring Slim (2024) packs improved health-tracking capabilities

From a health-tracking perspective, Circular says its newest smart ring sports an upgraded sleep algorithm. This allows the wearable to monitor your heart rate, SpO2 levels, temperature, and breathing rate while sleeping for deeper sleep analysis. The company even claims its new algorithm provides 79% accuracy in recognizing sleep disorders.

Another highlight is the new heart rate during sport algorithm, which will apparently accurately track your heart rate during sporting activities.

Alongside the Ring Slim (2024), Circular also launched Kira+. An upgraded version of Kira, the new app uses “circles” to help you track and analyze all your health data.

Unlike some other smart rings, the Circular Ring Slim (2024) does not require any monthly subscription. You pay €259 for the wearable and gain access to all its features.