The Only Smart Ring With
ECG Tracker & AFib Detection
Ciicular Ring 2 is the world’s first ECG tracker on your ring with 13+ other features. Run a 40-second ECG anytime from your finger. See the insights get actionable comments.
Check Your Heart Rhythm In 40 Seconds
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.
Annual Checkups Aren’t Enough
A yearly visit captures one moment. Your heart rhythm can change between appointments.
Symptoms Often Come Late
By the time palpitations, fatigue, or breathlessness appear, the issue may already be developing.
Subscriptions Add Friction
Some trackers charge monthly fees to unlock key health insights—turning access into an ongoing cost.
A Smarter Way To Track ECG & AFib
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.
Check Beyond Appointments
Run an on-demand ECG anytime or anywhere.
Earlier Awareness
Check when something feels off, not only after symptoms grow.
No Monthly Fees
Your ECG insights stay accessible without extra cost.
40-Second Readings
Fast, on-demand ECG from your finger.
Ring-Form Comfort
A discreet way to wear ECG daily.
More Than ECG
13+ health features in one ring.
The Only Smart Ring With ECG
See How Circular Compares
Circular Ring 2
Apple Watch Series 9
Samsung Galaxy Watch
Whoop
ECG heart rhythm check
No
Yes
Yes
AFib pattern detection
No
Yes
Yes
Smart ring form factor
Yes
No
No
On-demand readings
-
Yes
Yes
Shareable PDF report
-
Limited
No
No monthly subscription
No — $5.99/mo
No — some features
No — some features
Battery life
8 days
18 hours
Up to 40 hours
Sleep + HRV + stress + ECG combined
Partial — no ECG
Partial
Partial
Titanium body, waterproof
Yes
No
No
When People Use Circular Ring 2 to Track Their ECG
A Sudden Flutter During The Day
You feel an unexpected irregular beat during work or rest. Instead of ignoring it, you run a quick ECG and check your rhythm immediately.
After A Stressful Period
Long days, pressure, and fatigue build up. Your heart feels different, and you want to understand if stress is affecting your rhythm.
Following Poor Sleep
After several nights of weak sleep, your body feels off. You check your ECG to see how your heart is responding.
Post-Workout Check-In
After an intense session, your heart feels unusually strained or inconsistent. You take a reading to better understand your recovery state.
After A Previous Warning
A past alert or doctor conversation stays in your mind. You use ECG to monitor your rhythm more regularly and stay aware.
When Something Just Feels Off
There is no clear symptom, just a sense that something is not right. Instead of waiting, you check and get clarity in the moment.
More Than An ECG Tracker. 13+ Features Included
ECG tracker on your fingers 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. Now instead of getting simple data that you need to figure out yourself, you get it but analysed explained and packed with actionable insights and all that for free.
That means more context, more value, and a smarter way to understand your health every day.
Technical Specifications
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, your AI health coach
One reading is a moment. Kira watches the whole picture.
Kira, the Circular AI health coach, watches all of your health signals every day. Translaties 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.
From people who wear it
Martin
4.9
I'm super happy about the features, looking forward to wearing this. Photoplethysmography ppg measures the volume of blood flow, basically diastolic and systolic with light. ECG is the electrical measure. So it seems they complement each other for the capabilities the ring will have.
Designed Not to Distract
4.9
No lights, no buzzes, just a luxury, stylish ring that fits seamlessly into your daily life with no distractions.
Kristin
4.9
As a cardiology professional (hospital turned med tech), of 19 years, the EKG feature is the one I cannot wait for!! Exactly what I've been waiting for.
Questions about ECG tracking
Is Circular Ring 2 really the only smart ring with ECG? As of 2025, yes. Circular Ring 2 is the first and only smart ring to offer on-demand ECG readings and irregular rhythm detection. How do I take an ECG reading with the ring? Open the Circular app and navigate to the Heart Rhythm circle. In your ring settings, confirm which hand the ring is on. Then place a finger from your opposite hand on the small sensor dot on the ring's face and hold still for 40 seconds. The app will process the waveform and display your result.
Why do I need to touch the ring with my other hand?
Opposite finger completes circuit across chest (Lead I equivalent), enabling heart signal detection.
What results can the app show?
After each 40-second reading, the app classifies your rhythm as one of the following: normal sinus rhythm, possible AFib, possible tachycardia, possible bradycardia, or unclassifiable. Each reading also generates a PDF report formatted for physician review.
What should I do if a reading flags an irregular rhythm?
The recommended next step is to share the PDF report with your doctor for confirmation. The app does not diagnose conditions. It surfaces patterns that may be worth discussing with a medical professional.
How accurate are the readings?
For best accuracy, take readings while seated and at rest, in the same conditions you would be asked to maintain in a clinical setting. Movement, dry or cold fingers, post-exercise state, or a loose ring fit can reduce signal quality. If the reading is poor, the app will notify you and suggest trying again.
How often should I check my heart rhythm?
For general wellness monitoring, once or twice a month is a reasonable baseline. If you have a known history of arrhythmia, or if your doctor has recommended more frequent monitoring, daily readings are fully supported with no cooldown between sessions.
Does this feature require a subscription?
No. ECG tracking is included with the Circular Ring 2 at no additional cost. There is no monthly fee to access this feature or any other core feature.
How is this different from Apple Watch ECG?
Apple Watch also offers single-lead ECG. The key differences are form factor, battery life, and pricing model. Circular Ring 2 is a ring, which many users find more comfortable for continuous wear. It lasts 8 days on a single charge compared to Apple Watch's 18 hours. And it requires no subscription for core features, where some Apple Watch health features require an Apple subscription tier.
Is this the same as a hospital ECG?
They use the same underlying electrical measurement principle. A hospital ECG typically uses 12 leads simultaneously to build a detailed map of the heart's electrical activity. Circular uses a single-lead measurement, which is the same approach as most consumer ECG wearables. Single-lead readings are effective for detecting rhythm irregularities. They are not a substitute for a full clinical evaluation.
What are all the features/signals Kira can relate to ECG? Please list all confirmed links, not assumptions.
Everything in your sleep and energy and stress circles. HRV/stress, sleep/recovery, respiratory rate/SpO2, activity load, energy trends, manual notes.
Does the ring store raw ECG waveform data, or only processed results?
Raw waveform for PDF; stores processed results/trends.
Does Kira interpret ECG data directly, or is ECG handled separately from Kira? If Kira does interact with ECG, what exactly does it do?
Kira analyzes post-reading, correlates with vitals, gives summaries/pattern
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