Circular Ring 2
Circular Ring 2 is the only smart ring with a built-in ECG tracker. Run a 40-second ECG anytime, directly from your finger. Get clear, actionable insights.
Your heart can feel different in an instant and uncertainty can stay with you for hours. Circular Ring 2 lets you run a 40-second ECG directly from your finger, so you can check your rhythm when the moment happens, not after it has passed. You get fast, clear insight that helps you understand what is going on and decide your next step with more confidence.
Recording · single lead
62bpm
Duration
40 s
Signal
Good
Result
Regular rhythm
A yearly visit captures one moment. Your heart rhythm can change between appointments.
By the time palpitations, fatigue, or breathlessness appear, the issue may already be developing.
Some trackers charge monthly fees to unlock key health insights—turning access into an ongoing cost.
Circular Ring 2 gives you a faster, simpler way to check your heart rhythm without waiting for an appointment, relying on late symptoms, or paying monthly to access key insights. With a 40-second on-demand ECG from your finger, you can check in when questions come up and keep a clearer view of your heart over time.
Run an on-demand ECG anytime or anywhere.
Check when something feels off, not only after symptoms grow.
Your ECG insights stay accessible without extra cost.
Fast, on-demand ECG from your finger.
A discreet way to wear ECG daily.
13+ health features in one ring.
See How Circular Compares
| Feature | Circular Ring 2 | Apple Watch Series 9 | Samsung Galaxy Ring |
|---|---|---|---|
| ECG Sensor | Yes (dedicated electrode) | Yes (wrist electrode) | No |
| AFib Detection | Yes | Yes | No |
| ECG Reading Time | 40 seconds | 30 seconds | - |
| Shareable PDF Report | Yes | Limited | No |
| ECG + All Health Data in One App | Yes | Partial | No |
| Battery Life | Up to 8 days | Up to 18 hours | Up to 7 days |
| Water Resistance | IP68 | WR 50M | IP68 |
You feel an unexpected irregular beat during work or rest. Instead of ignoring it, you run a quick ECG and check your rhythm immediately.
Long days, pressure, and fatigue build up. Your heart feels different, and you want to understand if stress is affecting your rhythm.
After several nights of weak sleep, your body feels off. You check your ECG to see how your heart is responding.
After an intense session, your heart feels unusually strained or inconsistent. You take a reading to better understand your recovery state.
A past alert or doctor conversation stays in your mind. You use ECG to monitor your rhythm more regularly and stay aware.
There is no clear symptom, just a sense that something is not right. Instead of waiting, you check and get clarity in the moment.
Titanium body, hypoallergenic interior
2.55mm thick, 7.8mm wide, 3 grams
Sizes: US 6–14
Battery: 8 days (Power Mode), 5 days (Performance)
Charging: 30 mins via wireless charger
ECG, PPG, temp sensor, 3x accelerometer
Bluetooth Low Energy, Airplane Mode
iOS & Android compatible
GDPR & HIPAA compliant
Kira, the Circular AI health coach, watches all of your health signals every day. Translates in plain language, explains what your data actually means for your life and shares actionable insights. She does not just surface numbers. She provides context.
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★★★★★4.9
"Came for the ECG, that was it, that was the whole plan. First week Kira hit me with: your sleep is wrecking your stress recovery way more than your workouts are helping it. Bro. I restructured my entire week after that one sentence. Still think about it honestly."
★★★★★4.8
"My mum is 68 and very particular. Anything that looks like a health device goes straight in the drawer. This didn't. She wore it, figured out the ECG herself, and showed her doctor. I couldn't believe it."
★★★★★4.9
"First pregnancy and my body just feels different every week. Started using Circular to understand what's actually changing. The ECG, sleep, stress all together. Kira basically became my daily check in. I didn't expect to rely on it this much."
ECG tracker on your finger is only the beginning. Circular Ring 2 brings together 13+ connected health features, including sleep, stress, HRV, activity, SpO₂, temperature, energy, cycle, and many more paired with actionable AI insights.
One signal tells you something. Thirteen together tell you everything.
Your complex data, turned into clear tips tailored to your lifestyle.
Oxygen levels and breathing patterns tracked while you sleep.
Cycle, symptom, and hormonal tracking with high precision.
Energy usage based on real activity and body data.
Learn when your body is stressed and needs rest or when it is ready to perform
Stress insights showing when your body needs rest or is ready to perform.
Circular Ring 2 is not intended to diagnose, treat, cure or prevent any disease, and is not for use in an emergency.
More in the help centre.
Yes. Circular Ring 2 has a single-lead ECG sensor that records your heart's electrical activity during a 40-second check. You start each recording yourself. ECG does not run continuously in the background.
Touching the ring's outer electrode with your opposite hand completes the electrical circuit needed to record your ECG. Keep contact throughout the recording and follow the hand position shown in the app.
Your recording can show:
These results describe the recording. They do not provide a diagnosis.
Save the report and share it with a healthcare professional, especially if irregular results repeat. For possible AFib, seek clinical review. If you have chest pain, breathlessness or fainting, seek emergency help instead of waiting for another reading.
Reading quality depends on fit, skin contact and movement. For the best recording, sit still, support your arms and keep your hands warm and dry.
A normal result cannot rule out every heart condition.
Circular suggests monthly checks for healthy adults aged 40 and over. If you have symptoms, risk factors or an existing heart condition, ask your clinician what schedule suits you. Each ECG captures only the time you record.
No. ECG recordings and downloadable reports are included with Circular Ring 2, without a mandatory subscription.
Both offer an on-demand, single-lead ECG and PDF reports you can share with your doctor.
The main differences are the device format, phone compatibility and recording time.
No. Circular records one electrical view of your heart. A standard hospital ECG uses 12 leads to examine it from multiple angles. Your ring's report can support a conversation with your clinician, but it cannot replace that examination.
Kira's inputs include your ECG readings, alongside:
Circular shows an ECG waveform and lets you export the trace as a PDF, so you receive more than a result label. Its August 2026 update also introduced clearer waveform rendering and richer ECG reports.
The Heart Rhythm feature provides your ECG recording and rhythm result. Kira provides broader health insights and lifestyle recommendations.
Take a reading whenever you want one. No subscription, no limit.
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