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4.5
Circular Ring 2 combines a jewelry design with tracking of 140+ biosignals across 13+ health features — including ECG, AI coaching, sleep, activity, recovery and more. A health lab on your finger, with a subscription-free experience and premium features like blood pressure and glucose trend coming soon.
Clinical-level ECG & AFib Detection
On-demand heart rhythm monitoring.
Kira™ AI Health Coach
Actionable insights and wellness suggestions tailored to your body.
No Subscription Fees
All vital features included. No hidden costs.
Pick your color
Pick your size
6
7
8
9
10
11
12
13
14
Or don't know your size?
Buy with Sizing Kit
Extra Peace of Mind?
yearly
Extra protection. Covers accidental damage, loss, and full replacement. One per ring.
Features
Blood Pressure Monitoring
Track your blood pressure trends. Understand how stress,
sleep, and activity affect your heart health over time.
Coming as a premium feature in late 2025.
Glucose Trend Monitoring
Stay ahead of your blood sugar fluctuations with non-invasive tracking. Ideal for those managing energy levels, metabolism, or early glucose sensitivity. Planned for early 2026, as a premium feature.
ECG + AFib Detection
Track your heart rhythm with world’s first medical-grade technology and catch signs of arrhythmia before symptoms appear.
Sleep Tracking
Monitor sleep stages, breathing, and oxygen levels to understand how well your body recovers overnight.
Women’s Health
Keep track of your cycle, hormonal shifts, and fertility with personalized insights based on your vitals.
Stress & Energy Monitoring
See how stress affects your body and get guidance on when to rest or push harder.
Advanced analytics
Make graphs overlap and understand how different metrics are linked.
Energy monitoring
Get stats and in depth insights about your energy levels.
Live measurement
On-demand spot measurement for HR, SpO2, HRV, activity intensities, and Max HR.
Alarm clock
Wakes you up with a smart alarm during your lightest sleep stage.
Guided breathing
Launch guided breathing exercises to relax, sleep better, and more.
Vital alerts
Get notified when you vitals are going off.
Medication
Never forget to take your meds anymore and keep track of your intakes.
Coherence
Dive into a state of optimal function and regulate your emotions and clarity.
Sport Sessions
Track outdoor activities with a GPS trace and reports.
Airplane Mode
Disable ring’s Bluetooth communication.
Timer
Set a timer for your workout or anything else.
Calendar
Add manual notes that are reflected in the app and add context to your data.
Heart Rate + HRV
24/7 heart rate & morning resting heart rate and heart rate variability.
Breathing Rate
Breathing rate during sleep periods.
Blood oxygenation
Medical grade SpO2 levels during sleep & rest periods.
Temperature
Temperature variations trends help detect fever, menstrual cycles.
Kira™ Coaching
Your AI health coach turns complex data into clear, actionable tips tailored to your lifestyle.
Battery & Charging
Wear it for up to 8 days straight. Then wirelessly recharge in just 30 minutes.
What's in the box?
Circular Ring 2
Wireless Charging Case
USB-C cable
Cleaning Cloth
App Access
Digital User Guide
Technical Specs
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
Because
Premium
Means
Protected
Free Worldwide Shipping
for any non-discounted order
Free 14-Day Return
1-Year Warranty
24/7 Support
Free Worldwide Shipping
for orders >$349
Free 14-Day Return
1-Year Warranty
24/7 Support
13+ Advanced
Health
Features
Every key signal your body gives — tracked, analyzed, and translated into real guidance.
Designed Not to Distract
No lights, no buzzes, just a luxury ring that fits seamlessly into your daily life with no distractions.
Battery & Charging
Wear it for up to 8 days straight. Then wirelessly recharge in just 30 minutes.
The Case That Powers Your Ring
Your ring comes with its own sleek charging case. It protects, powers, and extends durability without the need to plug in.
You wear the ring. The app listens.
Kira
responds.
The ring captures over 8 key health signals and the app turns those readings into clear, easy to understand insights. You see patterns in your recovery, energy, stress, and sleep without needing to decode anything.
And then, Kira, your AI health coach, watches for any changes in your vitals, spots early warning signs, and sends you gentle, helpful recommendations. No searching. No guessing. Kira already knows what matters and what to do next.
Technical Specs
2.55mm thick, 7.8mm wide, 3 grams
Sizes: US 6–14
Fully Waterproof
Withstands daily use in the shower, pool, or rain
Battery: 7 days
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
Titanium body, hypoallergenic interior
Finished with a durable PVD coating protecting it from scratches and wear.
Titanium body, hypoallergenic interior
Finished with a durable PVD coating protecting it from scratches and wear.
Trusted by People Who
Live Well
Choose your
color
What people say about
Circular?
Blood Pressure & Glucose is a dream
4.9
I'm super happy about the features, looking forward to wearing this. I'm super excited for Blood pressure and Glucose. It's crazy that you can do that with such a small technology.
Designed not to distract
4.9
No screen, no buzzes, just a stylish ring that fits seamlessly into my daily life with no distractions.
EKG is a nice addition!
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.
What’s in the
Box
Circular Ring 2
Wireless Charging Case
USB-C cable
Cleaning Cloth
App Access
FAQ
What makes Circular Ring 2 different from other smart rings?
Circular Ring 2 combines industry-leading accuracy with a lightweight titanium design. It measures over 13+ health features and 140+ biometrics, with data updating up to two minutes. Unlike trackers that only show numbers, Circular pairs data with Kira, your personal AI health coach, who translates trends into simple, actionable advice. See Circular experience as a health lab at your finger.
Does Circular Ring 2 require a subscription?
No. All 13+ health core features and 140+ biometrics are free forever. Only a small number of premium features use a freemium model (free & paid part with coins or money).
All the core features are free, with no subscription required. These include:
ECG (40-second heart rhythm check)
Sleep tracking (including sleep stages)
Energy trackingSmart Alarm (with phone's vibration)
Vital alerts for irregular changes
Guided breathing sessions
Stress tracking & predictions
Chronotype analysis
Women’s health tracking (cycle, fertility, hormonal phases)
24/7 activity tracking and sport sessions
HRV (Heart Rate Variability) monitoring
Skin temperature trends
Blood oxygenation (SpO2) during rest and sleep
Live measurement of HRV and heart rate
Personalized wellness recommendations
Immunity index and medication reminders
Coherence (emotional regulation training)
Premium features are available in two ways:Pay directly (classic premium subscription).
Use Circular Coins (earned by daily use of your ring).
Premium features include:Blood pressure (two-tier model: free score & detailed trends + premium)
Blood glucose trend (coming 2026)
What are Circular Coins?
Circular Coins are our way of rewarding you for staying consistent and improving your health.
You earn coins by using your ring daily.
You can use them to unlock premium features and real-life benefits.
No crypto, no trading — just loyalty rewards inside the app.
Current users will have time to collect coins before premium features launch.
How does blood pressure tracking work?
Circular Ring 2 is the first smart ring equipped with both PPG (photoplethysmography) and a single-lead ECG sensor, enabling blood pressure estimation.
Circular Ring 2 uses a technique called Pulse Transit Time (PTT) to estimate blood pressure. This method is commonly used in clinical research to track blood pressure trends without a cuff.
How it works:
The ECG sensor detects the electrical signal of a heartbeat (R-peak).
The PPG sensor detects the arrival of the pulse at the finger.
The time delay between these two events is known as Pulse Transit Time (PTT).
PTT is inversely proportional to systolic blood pressure.
Based on this delay, Circular calculates an estimated blood pressure value.
To enhance accuracy, users must perform a calibration using a traditional blood pressure monitor once every month.
Blood pressure measurement is done via a 60-second spot test, during which the user is required to touch the ring with a finger from the opposite hand to activate the ECG and complete the circuit.
Circular provides a daily blood pressure estimate as a wellness indicator, perfect for tracking trends related to stress, recovery, and lifestyle.
Not a diagnostic tool. This feature offers informational wellness guidance only and should not replace clinical evaluation.
We designed a two-tier blood pressure feature:
Free version: a simple, color-coded BP score for quick daily insights.
Premium version: detailed numbers, graphs, and Kira’s context, showing how BP relates to your sleep, stress, and activity trends.
This hybrid model keeps essentials free while covering the costs of advanced algorithms and cloud processing required for in-depth analysis.
How accurate is the data?
Circular Ring 2 uses industry-leading sensors and algorithms, tested against gold-standard equipment. Updates every two minutes ensure both precision and responsiveness, whether you’re resting or active.
What is Kira, and how does she help me?
Kira is your personal AI health coach inside the app. She:
Translates your vitals into clear, simple recommendations.
Spots early warning signs before you notice them.
Helps you understand patterns in sleep, stress, recovery, and energy.
Learns your body during a short calibration period (about 14 days) to tailor insights to you.
Is the ring waterproof?
Yes. Circular Ring 2 is fully waterproof, safe for swimming, showering, and daily wear.
What is the ring made of?
The outer body is crafted from ultra-light titanium with a PVD coating (for premium finishes like gold and rose gold). The interior is hypoallergenic, safe for sensitive skin, and designed for comfort 24/7.
How long does the battery last?
A quick 30-minute charge gives you up to 8 days of use. Actual battery life depends on how you use the ring:
Power mode (all-day tracking + nightly sleep tracking): around 7-8 days.
Performance mode (high-frequency measurements, workouts): around 4-5 days.
What sizes are available?
Circular Ring 2 comes in a full range of sizes from 6 to 14. You can order your ring with a Sizing kit and try all available sizes before receiving your ring to ensure a perfect fit.
Where can I see my data?
All insights are available in the Circular app (iOS and Android). You’ll see clear graphs, scores, and personalized recommendations.
Is my data secure?
Yes. Your data belongs to you.
Protected with end-to-end encryption from ring to app to cloud.
Stored and processed on secure servers that comply with strict European and international standards (like GDPR).
You can delete your data anytime in the app.
We never sell or share your health data.
When will new features like blood pressure and glucose tracking be available?
Blood Pressure: rolling out by the end of 2025.
Blood Glucose: planned for early 2026.
All other features are available instantly.
Can I travel with Circular Ring 2?
Yes. The ring is airplane-safe and meets all global certifications. It even includes an airplane mode to turn off Bluetooth while still collecting data.
How does the ECG feature work?
You can take a 40-second ECG anytime, anywhere. It records your heart rhythm and gives you a reliable snapshot of your heart’s electrical activity. Results appear instantly in the app, and you can export and share your results in PDF format.
Can Circular Ring 2 track stress?
Yes. Stress levels are estimated through heart rate variability (HRV) and other vitals. Kira then helps you see what might be driving your stress and suggests practical breathing or recovery techniques to bring balance back.
What is the Energy Score?
The Energy Score combines data from your sleep, recovery, and activity into one simple measure. It shows when you’re ready to perform and when it’s better to slow down.
How does the smart alarm work?
The smart alarm tracks your sleep cycles and wakes you during your lightest sleep stage, with your phone's vibration, so you start the day feeling refreshed instead of groggy.
Can the ring track my workouts?
Yes. Circular Ring 2 automatically tracks your daily activity and supports manual sport sessions with GPS. It monitors workout intensity, heart rate zones, calories — so you know if your training is paying off.
How does sleep tracking work?
The ring tracks your sleep in detail, including total duration and deep, light, and REM stages. It also monitors your breathing rate, heart rhythm, and SpO₂ overnight. After the short calibration period, you’ll start receiving a Sleep Score and clear sleep trends.
Does the ring monitor my breathing?
Yes. Circular Ring 2 records your breathing rate during sleep. This helps highlight recovery quality, altitude adaptation, or unusual patterns that may affect your rest.
What about body temperature?
The ring tracks skin temperature trends. This can help identify fever, monitor recovery, and provide insights into menstrual cycle phases or hormonal shifts.
Can it help with women’s health?
Yes. Women’s health tracking is built in. It monitors your cycle, fertility windows, and hormonal phases using your body’s signals, not just calendar predictions.
How does blood oxygen tracking help me?
Circular Ring 2 measures SpO₂ levels during sleep and rest. This shows how well your body is oxygenated, which is important for sleep quality, altitude changes, and overall recovery.
What are Vital Alerts?
If something unusual happens in your vitals — such as a sudden heart rate spike or drop — Circular sends a Vital Alert. These phones' notifications help you log, keep a history, and catch changes early so you can take action.
What is Coherence training?
Coherence is a guided practice for emotional clarity and calmness. It helps you regulate your breathing and heart rhythm, making it easier to manage stress and improve focus.
Can I get personalized recommendations?
Yes. Beyond raw numbers, Kira connects the dots across your sleep, stress, recovery, and activity. She translates them into clear, tailored steps that fit your lifestyle.
Does the ring remind me about medication?
Yes. You can set up medication reminders in the app to track your medication intakes. Subtle notifications from your phone's vibration help you stay on track without disrupting your day.
Complete Your Experience
A little extra goes a long way.
- TToniVerified ReviewerRated 5 out of 5 stars51 seconds agoJust received the ring!
First impression is good : the ring looks and feels premium.
Fitting is perfect. I opted for 3d-printing a couple of candidate sizes. This solution seemed to me to be more sustainable than ordering a sizing kit and more reliable than the online tool.
Syncing and first firmware update went smoothly.
Can't wait to complete the calibration period and to put Kira's insights to the test 😜
So far very satisfied.
- HAHuda A. S.Verified BuyerRated 5 out of 5 stars1 week agoBattery life is better than my samsung watch and the app is way easier
I used samsung watch before and I had to charge it every 3-4 days. The Circular ring lasts almost a week, and it charges fast in the case. App feels simple, no endless menus. Kira even told me my late-night wine was hurting my recovery (ouch, but true).
CCircular3 days agoHey Huda,
Thank you so much for sharing your experience! We’re thrilled to hear that you’re enjoying the battery life, the app, and Kira’s insights. 🙂 Your feedback means a lot and helps us keep improving the Circular experience. - PKPaul K.Verified BuyerRated 5 out of 5 stars1 week agoDevice great, but app drains phone battery a LOT. They are lyer on blood pressure being paid
No issues
CCircular3 days agoHello Paul,
Don’t forget to close the app running in the background to avoid excessive battery drain. :)
Regarding blood pressure tracking, a free version of this feature will be available when the feature officially launches. - MAMoritz A.Verified BuyerRated 4 out of 5 stars1 week agoI didn’t expect to love it this much after the long wait
I backed on Kickstarter and had to wait ages, but honestly the final product is worth it. Battery lasts 6 days, data is clear, and the design is elegant. I almost forgot I’m wearing it.
CCircular3 days agoHey Moritz A,
Thank you so much for sharing your experience! We’re thrilled to hear that you’re enjoying your ring and that it’s living up to the wait ! Your feedback means a lot and motivates us to keep improving the product. - JTJack T.Verified BuyerRated 5 out of 5 stars1 week agoI finally stopped wearing watches and I don’t miss them
The ring is tiny compared to the watches I had. Feels invisible, even at night. I wear it 24/7. Showered, ran, even swam with it and i got no problem at all. I get a full week of battery life in power mode. But if you go for peformance mode then it's only 3 days or so.
CCircular3 days agoHello Jack,
Thank you so much for your feedback! You’re right, in performance mode, the battery is lower and typically lasts around 4–5 days. We’re glad to hear you’re enjoying wearing the ring 24/7!