Circular Ring 2

Overview

The Circular Ring 2 is a titanium smart ring that made its name as the first on-finger ECG ring with AFib detection, adding a clinical-grade single-lead ECG to a PPG + skin-temperature + accelerometer sensor stack that tracks 140+ biosignals. Announced at CES 2025 and shipping through 2025, it pairs an 8-day battery and 50m water resistance with a fully subscription-free model, exposing sleep, HRV recovery, stress and temperature insights through the Circular app's Kira AI coach. Priced from $349 (Obsidian Black) to $549 (Gold/Rose Gold), it targets buyers who want medical-grade heart monitoring and no recurring fees in a 2.55mm-thick titanium band.

✨ Key Highlights

• World's first smart ring with an on-finger single-lead ECG sensor and AFib detection — FDA-cleared, with blood-pressure insights derived from the ECG (the only smart ring carrying both ECG and PPG sensor suites)
• Premium titanium build with a hypoallergenic interior and durable PVD coating; 2.55mm thick and 7.8mm wide, waterproof to 50m (5 ATM) and light enough to wear 24/7
• Sensor suite: single-lead ECG, 3-LED PPG (heart rate + SpO2), digital skin-temperature sensor, and 3-axis accelerometer (IMU) tracking 140+ biosignals
• Up to 8 days of battery in Power mode (roughly 5 days in Performance mode) with a fast ~30-minute full charge, plus digital sizing so you can size your ring from home before it ships
• No subscription: sleep staging, HRV recovery, stress, temperature and Kira AI coaching are all included in the purchase price, unlike Oura's paid membership