CIRCUL RING
CIRCUL RING
- Automatic Sleep Apnea Monitoring
- Effortlessly track your sleep apnea with precise monitoring. The smart ring detects breathing irregularities and provides valuable insights into your sleep quality—no additional devices required.
- Next-level Accuracy of Health Metrics
- Born from 10+ years of medical research, CIRCUL has evolved through four generations of refinement, each iteration smarter, lighter, and more precise than its predecessor.
- No Subscriptions. Free Full Monitoring
- Enjoy full monitoring without any subscriptions or hidden fees. Get lifetime access to all features with just a one-time purchase.
- One-time purchase, lifetime access.
- Utilizes anomaly detection algorithms to promptly identify potential health risks.
- Continuously tracks data to generate detailed health reports.
- Exclusive WEB personal data center.
Product specifications
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Size
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S/M/M+/L
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Weight
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S:5.6g M:6.5g M+:6.8g L: 7.1g
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Charging interface
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Input voltage: 5V
Input current: 12-20mA
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Waterproof class
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5ATM
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Charging box battery
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230mAH
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Charging box weight
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38g
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Warranty
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1 year
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How to Choose Your Size
We offer two methods to measure your ring size.
Method 1: Measure and confirm your ring size following the guide below.
Step1
Take a length of floss or string and wrap it around the base of your finger.
Step2
Mark where the floss or string first overlaps with a pen.
Step3
Stretch the length of string out along a ruler or measuring tape, and take down the length in millimeters
Step4
The length you measured is the circumference of your finger, compare the circumference of your finger the following table.
Circumference(mm)
Method 2: You can download the provided PDF file below, print and cut it out for a more convenient way to measure your ring size.
This policy applies to products on circulsense.com, sold only to end-users.
Only items purchased directly from our site can be returned or refunded. Products from other retailers follow their own return policies. For the best fit and data from your CIRCUL RING, please buy directly from our website.
Return
Our policy does not support returns or exchanges without valid reasons, and return requests must be made within 30 days. Valid reasons for a return include:
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The product has defects or damages upon delivery.
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The delivered product is different from the color you selected.
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The delivered product significantly differs from the description provided at the time of order.
To comply with our return policy, please ensure:
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The product is in its original condition, unopened, and unused.
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If you find defects, damages, or discrepancies, provide photos to support your claim.
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Submit a return request to our customer service team within 14 calendar days after delivery. Our team will review your request, and if approved, you will have 14 calendar days to return the product.
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Repackage the returned product with all accessories and documents included when you received it.
Please note: You will be responsible for all costs associated with returning the product unless the return is due to defects, damages, or non-compliance with specifications. In such cases, shipping fees, handling fees, or taxes paid will not be refunded.
Exchange
If the delivered product is in its original condition and unused, but you wish to exchange it for a different size or color, we recommend submitting a return request and placing a new order. You will be responsible for all costs associated with the return. Unless the return is due to defects, damages, or non-compliance, shipping fees, handling fees, or taxes paid will not be refunded.
Refund
A full refund means you will receive the total amount of your order back if you return the product according to our return policy.
You may be eligible for a partial refund if:
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We find any damages, contamination, wear and tear, or missing parts upon inspecting the returned product. We may deduct the devaluation amount from your refund unless these issues were declared in your return request.
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You received bundled products or gifts. To receive a full refund, we recommend returning all bundled items. If you cannot return them, we may deduct the corresponding amount from your refund.
Please note: You will be responsible for all costs associated with returning the product unless the return is due to defects, damages, or non-compliance, and you have provided supporting photos and descriptions.
Processing Time for Returns or Exchanges
For return requests that comply with our policy, we will initiate the refund immediately upon receiving the returned product. The refund will be processed through the original payment method and may take up to 10 calendar days.
Warranty Coverage for CIRCUL RING
All original components of new products are covered by a one-year warranty in non-European Economic Area (EEA) countries and a two-year warranty in EEA countries. Claims must be made directly to CIRCUL with proof of purchase. The warranty applies to the original owner and is transferable to subsequent owners. If damage is due to craftsmanship defects, CIRCUL will repair, replace, or refund.
Exclusions from Warranty Coverage
The warranty does not cover:
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Improper or negligent use, operation, or modification.
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Maintenance contrary to product care instructions.
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Normal wear and tear.
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Rechargeable batteries, which have limited lifespans and are considered consumable items. Battery replacement is not included in the standard warranty.
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Damage or defects caused by accidents.
From Earth to Space
World's First Smart Ring to Conquer Space -
Blue Origin's Trusted
"CIRCUL+ joined Blue Origin's NS-20 mission in March 2022, as Professor Jim Kitchen chose our 1st generation smart ring to track his vital signs data in space—for his UNC classroom."
Overview
HRV Precision.
Millisecond Accuracy
One Ring, Any Finger
5 ATM
Water-resistance
Sleep Apnea
Analysis
A Clinical Lab
Wrapped around
Your Finger.
Up to 7 days
Adaptive design
24/7 All-day comfortable fit
Multiple excercise models
SST™ Ultra 2.0 sensors
Subscribe for FREE !
Continuous SpO2 Tracking
How we compare
| Product | CIRCUL | Oura Ring 4 | RingConn Gen 2 | Apple Watch Ultra |
|---|---|---|---|---|
| Price |
Price
$249
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$349
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$299 | $799 |
| Design | ||||
| Appearance |
Appearance
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| Ring Size |
Ring Size
Only 4 sizes
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12 sizes
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9 sizes | 3 sizes |
| Structure |
Structure
Elastic Design: Adapts well for stable, accurate monitoring.
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Fixed Design: reducing accuracy.
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Fixed Design: reducing accuracy. | Wrist-Equipped with an adjustable band |
| Sensors |
Sensors
Triple-Wavelength Photoplethysmography Sensor
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Heart Rate, Temperature, Accelerometer
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Photoplethysmography (PPG) Sensor, Temperature, Accelerometer | / |
| Monitoring Precision | ||||
| SpO2 Real-Time Measurement |
SpO2 Real-Time Measurement
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(no longer available on Apple Watch units sold by Apple in the United States since January 18, 2024) |
| SpO2 Continuous Measurement |
SpO2 Continuous Measurement
(with SpO2 Trend Graph) |
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| Heart Rate Data Update Interval |
Heart Rate Data Update Interval
1 second
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>10 mins
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>10 mins | / |
| Blood Oxygen Saturation Update Interval |
Blood Oxygen Saturation Update Interval
1 second
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>10 mins
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>10 mins | / |
| Exercise Heart Rate Update Interval |
Exercise Heart Rate Update Interval
1 second
(Accuracy close to a chest strap) |
Several Mins
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Several Mins | / |
*The comparison data may change over time. Features, specifications, and performance are subject to updates. Please verify with the respective manufacturers for the most accurate and up-to-date information.
All Features
Achieves millisecond-level accuracy, continuously analyzing heart rate variability, which is invaluable for evaluating overall health and stress levels.
Offers real-time tracking with second-level updates help users to assess respiratory health.
Updates data every second with an accuracy of ±2 bpm, providing highly accurate heart rate information to help users promptly identify cardiac health abnormalities.
Achieves an accuracy of ±0.1°C, updating every minute to quickly detect temperature anomalies, especially during menstrual cycle tracking and flu seasons or pandemics.
Sleep Apnea Detection: Capable of identifying the risk of sleep apnea, aiding in the early detection of potential sleep issues.
Lightweight design, support for sleep wear, provide complete sleep data
Real-Time Sleep Monitoring: Thoroughly analyzes sleep stages, including light, deep, and REM (rapid eye movement) sleep, offering detailed sleep quality reports to help improve sleep habits.
Supports monitoring up to 5 types of activities, such as running and cycling
Tracks exercise heart rate during workouts, providing real-time data and post-exercise analysis to help optimize performance.
Whether you're a runner or yoga lover, CIRCUL is designed to help you achieve your activity goals. With over 5 sports modes, it provides real-time heart rate feedback and detailed post-workout analysis. 90% of users report significant progress.
Provides real-time updates every two seconds, supporting heart rate tracking across various activities such as running, swimming, and cycling.
Achieving millisecond-level accuracy, providing continuous analysis of heart rate variability, which is invaluable for assessing overall health and stress levels.
Assesses stress levels through continuous high-resolution heart rate variability (HRV) metrics.
Offers de-stressing and relaxation recommendations based on stress data.
CIRCUL watches over you 24/7. Detecting arrhythmias and oxygen dips in real-time. Day or night, it's your silent guardian. Catch potential issues early. Stay ahead of your health.
More than numbers. ClRCUL reveals your wellness story. Heart rate trends. Sleep patterns. Stress insights. All in one comprehensive, shareable report. Empower your choices. See your health clearly.
“The adjustable size was important to me because my fingers sometimes swell, making other rings uncomfortable. I appreciate that this company has experience with smart rings and FDA approval, which should ensure better quality than newer brands.”
Gavin Hall
Medical Scientist
“My biggest problems with rings is the size. Finally, someone has invented the Smart ring that I can actually wear. My ex football teammates will be quite happy. Nobody has small finger joints that most fit rings over! Thank you!!!!”
Charlie Martin
Medical Scientist
“I’ve been looking for the RIGHT smart ring for some time now, this ring checks all the boxes for me. I’ve struggled with high blood pressure, rings fitting one day but not the next, so the adjustable size is awesome as well as continuous blood-pressure monitoring! ”
Robert Palumbo
Health and Wellness Coach
“This would be my first smart ring I think it’s the most stylish I’ve seen and I love the flexible design, for the functionality I am really looking forward to the health tracking I have some things that this rings tracking will help me with very much…I think this is why it’s a great product”
Benjamin Shullaw
Corporate Executive
“I like the ring because of the flexible sizing and being able to use different fingers. I also wanted one able to show BP and other medical functions. It is a nice looking ring and the colours available are very nice….Shared…”
James Lauzier
Freelancer
Parameter
Specification
S/M/M+/L(Covering refers to circumference)
S: 47-54.7mm,corresponding to US code 4-7;
M: 55.6-59.7mm,corresponding to US code 7.5-9;
M+: 60.9-66mm,corresponding to US code 9.5-11.5;
L: 67.5-76mm,corresponding to US size 12-15.5
Net weight
S:5.6g M:6.5g M+:6.8g L: 7.1g
HeadinPower sourceg
Internal power supply Built-in 3.8V Li-ion battery
Port
Bluetooth(5.0BLE, operating frequency 2.4-2.4835GHz; Modulation mode : GFSK; Frequency hopping: adaptive frequency hopping)
Charging interface
Input voltage: 5V Input current: 12-20mA
Attachment
Ring *1, Charging cradle *1, Type-C Charging cable *1, Manual *1
Waterproof class
5ATM
Charging box battery
230mAH
Charging case quality
38g
What's in the box
circul ring *1
Charging Cradle *1
Type-c charging cable *1
MANUAL *1
Still Got Questions?
Please read our FAQs page to find out more. Still have questions ? Contact our customer support.
The CIRCUL RING maintains a battery capacity above 80% after 300 cycles. It features Elite Modes specifically designed for users with sleep disorders or other conditions that require overnight blood oxygen monitoring. In this mode, it provides medical-grade SpO2 monitoring at 1-second intervals. Due to the increased power consumption from these intensive calculations, the battery life in this mode is approximately 3-7 days.
Additionally, the CIRCUL RING comes with a charging case that has an embedded battery, allowing you to charge the ring anytime. Charging time is approximately 60 minutes from 0% to 100%.
CIRCUL RING isn't just another smart ring—it's a revolution in personal health monitoring. As originated from the world's 1st FDA-cleared smart ring, it brings clinical-grade accuracy to your daily life. Our proprietarySST™(Sensor Stabilization Technology) ensures unparalleled data precision, adapting to natural finger size variations of up to 3mm throughout the day.
It provides Near-Medical-grade Health Data with Real-time Tracking at Second-level Intervals, ensuring that critical indicators such as heart rate, real-time blood oxygen, HRV, and blood pressure meet industry-leading accuracy standards.
- Heart Rate (24/7 Continuous monitoring)
- Blood Oxygen Levels (SpO2)
- High Precision HRV monitoring
- Sleep Apnea monitoring
- Temperature
- Blood Pressure (coming soon)
- Real-time Sleep Monitoring
- Exercise Heart Rate
- Activity Tracking
- Steps and Movement
- Energy & Stress
- Please put it into the charging case, and check if the ring has a blinking light.
- Please open the app and check whether the ring can be connected to it normally.
- Check for debris on the charging contacts.
- Try a different USB port or power adapter.
- Contact support if the issue continues.
