Circular Ring 2 Tracks 140+ Biosignals on Your Finger

The Circular Ring 2 packs a clinical-level health monitoring system into a titanium ring that weighs just 3 grams. Measuring 2.55mm thick and 7.8mm wide, it tracks over 140 biosignals across 13 health features, from ECG and AFib detection to sleep, stress, and heart rate variability, giving wearers a complete picture of their health without a bulky screen.

At the heart of the Ring 2 is its medical-grade ECG and AFib detection, the first of its kind in a smart ring. Built-in ECG, PPG, and temperature sensors, paired with a 3-axis accelerometer, monitor heart rhythm continuously and alert wearers to early signs of arrhythmia before symptoms appear. Sleep tracking logs stages, breathing rate, and blood oxygen levels through the night, while 24/7 heart rate and HRV monitoring add daily cardiovascular depth. Live spot measurements for SpO2, activity intensity, and maximum heart rate are available on demand at any moment.

The Kira AI health coach turns all that raw data into clear, personalized guidance. Rather than flooding users with numbers, Kira watches for changes in vitals, spots patterns across recovery, energy, and stress, and delivers specific recommendations in plain language. Advanced analytics let users layer metrics on the same graph to see how sleep connects to stress or how activity shapes overnight recovery.

The Ring 2 runs for up to 8 days on a single charge and refills in just 30 minutes through the included wireless charging case. Available in sizes US 6 through 14, the titanium body carries a hypoallergenic interior and a durable PVD coating that holds up against daily wear, water, pools, and rain. It pairs with both iOS and Android and meets GDPR and HIPAA compliance standards, keeping sensitive health data protected.

With no subscription fees for core features, and blood pressure monitoring and glucose trend tracking arriving as premium additions in 2026, the Circular Ring 2 is built to grow with its wearer over time. For anyone who wants a full health lab on their finger without the bulk of a traditional wearable, this ring delivers serious capability in a form that looks like fine jewelry.