This startup guide will take you through all the steps to setup your Circular ring 2.
Please read the user guide carefully before using your ring, charger, mobile app, and any other related Circular products and services. Failure to follow the instructions below could result in product damage, malfunction or injury and won't be covered by the warranty.
If you encounter any issues, head to our helpdesk.
Please read these carefully: wear instructions, care and maintenance, airports, secure buildings and magnetic scans, charging your Circular ring, safety information, and factors that may impair data accuracy.
Plug your charger: Insert the provided USB-C cable into the port on the back of the charging case, then connect the other end to a power source (laptop, power bank, phone, etc.) to charge the case's internal battery. To prevent your ring from overheating and ensure its longevity, please charge you ring with the charger's lid open.
Place your Circular Ring correctly on the charger following the indicator marks. The sensors of the ring must be north as indicated by the mark. Short press the button located on the back of the charging case to light the LED indicator, to wake up the ring and to start charging the ring.
Short press the button for 1 second, if the ring is placed correctly:
| Light | Meaning |
|---|---|
| 🟢 Green pulsing | Ring is charging |
| 🟢 Solid green | Ring is fully charged |
| 🔴 Red pulsing | Ring is charging but charger is low battery |
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Search for "Circular ring" on the App Store or Google Play. Once downloaded, follow the instructions to create an account and to pair your ring!
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When setting up your ring, pick "Gen 2" device. Once your ring is paired, it automatically tracks your metrics whenever you wear it.
When you open the app, it connects via Bluetooth Low Energy, which may take a few seconds since the connection only happens when the app is opened to save battery.
After opening your app, you'll see a loading bar while data is syncing on your home page. Data appears at the end of the synching process. You can also swipe down on the home page to trigger it manually.
You can wear Circular on any finger. It is best to wear Circular on the fingers of your non-dominant hand. Eg: If you are right-handed, wear it on your left hand.
The three middle fingers give the most accurate readings.
The sensor area of the Circular Ring (PPG sensors and electrodes) must be positioned on the palmar side of your hand — that is, under your finger. The Circular logo of the ring should be on top of your finger, visible from above.
Finger size can vary throughout the day, your fingers may swell in the morning or evening.
The Circular ring can be worn in the shower or when swimming.
It is not recommended to wear the ring in a sauna, hammam, or the sea for an extended time.
Do not wear your ring when handling domestic chemicals like washing dishes or non-domestic chemicals.
The Circular Ring 2 is waterproof and is IP68 grade. The ring can be immersed in 50 meters of water for a maximum of 30 minutes. It is not recommended for use in salt water.
Do not wear your Circular Ring 2 while handling hydroalcoholic gel or domestic chemicals such as bleach, disinfectants, cleaning products, hand sanitizer, or soap, or this can cause abrasion of the inner surface.
In case the ring gets stuck on your finger:
Watch out, finger size can vary throughout the day, your fingers may swell in the morning or evening!
In order to clean your ring and sensors, use a soft cloth or hand wash with mild soap and water. Mild soap in small amounts for very occasional cleaning is fine, if you dry the ring directly after.
DO NOT let moisture stagnate between the ring and the finger after wearing the ring if it was in contact with water. Please remove the ring from your finger and dry your finger and the inside of the ring with a cloth before wearing it again.
The outer surface of the ring may get scratches against harder metal jewelry or other objects in close contact made of harder materials.
It is not recommended to wear your ring during activities like weight lifting, CrossFit or carrying weight or heavy items. Damage may occur to the ring.
Dispose of the ring and internal battery in accordance with applicable laws and regulations. Special handling may be required. The charger is an electronic device and local legislation for electronics recycling should be followed.
The magnetic field created by metal detecting gates present at airports or entrances to secure buildings are known to harm electronic equipment, such as laptops, cell phones and the Circular ring. Security wands create the same magnetic pulse and can also damage your devices. Even a single exposure can impact your devices in a way that's not immediately visible.
You must send the Circular Ring with your electronic devices through the x-ray scanner with your carry-on.
You can check the level of the ring's battery by logging into your Circular app and looking at the top-right corner of the home page.
If your ring is on the charger and is fully charged, the charger LED will stop pulsing.
By default, when the charger is plugged into a power source with no ring in it, it will charge its internal battery automatically. The LED of the charger will be:
At the back of the charger, you'll find a button and a hole to allow certain sensors to operate.
To check the battery level of the charger (even when the ring is on it), press and hold the button for 2 seconds when the ring is not placed in the charger:
| Light | Charger battery |
|---|---|
| ⚪ No light | Battery empty |
| 🔴 Red light | Less than 30% battery |
| 🟠 Orange light | Between 30–70% battery |
| 🟢 Green light | Between 70–100% battery |
Calibration of the battery percentage level: Charge your ring to 100% for at least 45 minutes when you receive it for battery calibration purposes. Without that, the app may show incorrect battery level.
To charge your Circular Ring 2, you'll need to use the Circular Portable Wireless Charger included in your packaging, along with the provided USB-C charging cable. Please note that the charger voltage is 5V.
One charger size per ring size: The charger is designed for a particular ring size and cannot be used to charge other ring sizes.
Start by plugging the USB-C cable into the port located at the back of the charger. You can connect it to a computer, phone adapter, or wall outlet.
The charging case contains an internal battery to charge your ring even when unplugged—provided the charger's battery has remaining power.
It takes up to 60 minutes to fully charge your ring when the ring's battery is empty. Please note that the charger voltage is 5V.
The Circular Ring 2 will charge wirelessly when correctly placed on the charger and after pressing the back button.
Position your ring on the charging dock as shown in the illustration in the charging case, with the sensor of the ring positioned north. The ring's ECG electrodes must be placed in the notches of the charger guide.
If the ring is not aligned correctly, it will not charge.
Once the ring is placed properly, press the button once (short press: 1 sec) to initiate charging.
If placed properly:
Accuracy note: Circular developers compare accuracy against medical grade gold standard device while building each of the tracked metrics. Sleep against PSG, pulse oximeter for SpO2, Holter monitor for heart metrics and foot pods for steps.
For certain exercises, such as Crossfit, weightlifting or riding a bike, it may be difficult to auto-detect sport sessions. This is because when you're lifting heavy weights for an extended period of time or gripping something tightly, it's more difficult for the heart rate sensor to get a clear reading. This is because the sensor is being pushed against your skin which becomes compressed and harder to see through.
It is recommended to turn the flat part of the ring on the top of your finger during an activity as riding a bike or driving a car.
Another factor that can impair signal quality is temperature, as in cold weather blood can retreat from your fingers, which can also make it difficult for the heart rate sensor to get a clear reading.
Regarding heart metrics, Circular will only report average measurements per minute, so if the maximum Heart Rate is not sustained over a span of a minute or so, the minute-average will be lower than what other trackers can report, as they may report Heart Rate with higher temporal resolution.
There is a trade-off between higher temporal resolution and battery life.
The vibrations of your transportation on the road or on the rail line may sometimes transfer to your hand and look like steps to the ring. Especially when your ring-wearing hand is resting on the door, window or the steering wheel.
To ensure accurate ECG readings with your Circular Ring 2, it's important to follow a few best practices:
The Circular Ring 2 includes a single-lead ECG sensor that lets you take spot heart recordings to track heart rhythm and potential irregularities.
To begin, make sure your ring is properly paired and worn snugly. Then, go to My Ring > Wear the ring on my > Left or Right hand in the app to set the correct hand or the signal will be inverted.
Access a feature that needs the ECG. Place your thumb on the ring's outer surface. Sit still, relax your arm on your legs, and wait for the 40-second scan to complete without moving at all. This feature is designed for wellness tracking purposes only and is not a medical device or diagnostic tool. For any medical concerns, consult a healthcare professional.
Please note that Circular is not intended to diagnose, treat, cure or prevent any disease or medical condition without the assistance of a health professional. The information and guidance provided by Circular are there for informational purposes only and cannot replace the services of health professionals or physicians. You should always consult a health professional if you have any questions regarding any changes you intend to make to your sleep or activity or regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read through Circular services. Circular is not responsible for any health problems that may result from information or guidance you learn through the Circular services. If you make any change to your sleep or activity based on the Circular services, you agree that you do so fully at your own risk.
Please be cautious that the ring or any other Circular product you are wearing does not get caught on fixed structures or heavy objects when moving or moving heavier objects. Do not try to open the ring or puncture the ring or its battery.
Like with all rings made of metals, be careful when handling batteries when you are wearing the ring. If the electrodes of a battery are in contact with the ring, the battery may short circuit.
Keep the ring away from children. Do not leave the ring exposed to heat, such as in a vehicle under the sun.
If you experience redness or skin irritation on your finger due to the ring or any Circular product, remove it immediately. If symptoms persist longer than 2-3 days of not using your Circular product, please contact a dermatologist. The inside material of the Circular ring is medical grade biocompatible and gold plating on the charging contacts. There is no nickel in contact with your finger.
The full Circular experience requires Circular hardware products, internet access to the Mobile App and Websites, and other required software (if any). Periodic updates to any of these elements may be required for improved performance, and the performance of the whole may be affected by the performance of any of these elements. You are responsible for obtaining your own internet access and mobile device to access the Circular Services.
If you have any questions about getting started with or using your ring, mobile app and any other Circular services, or you have any issues with your product, please refer to the FAQs and the Helpdesk at helpdesk.circular.xyz.
If you can't find what you are looking for, send us an email to support@circular.xyz.
Except for the limited warranty for the Circular product set forth below, the Circular services are provided by Circular and its affiliates “as is.”
Neither Circular nor its partners, suppliers, or affiliates make any representations or warranties of any kind, express or implied, as to the operation of the Circular services (including the Circular products), its contents, or any information made available by or through the Circular services. In addition, Circular and its partners, suppliers, and affiliates disclaim all warranties with respect to the Circular services (including the Circular products), express or implied, including but not limited to the implied warranties of merchantability, title, fitness for a particular purpose, and non-infringement. Furthermore, Circular does not warrant that use of the Circular services will be uninterrupted, available at any time or from any particular location, secure or error-free, that defects will be corrected, or that the Circular services (including any Circular product) are free of viruses or other potentially harmful components.
Limited warranty for the Circular product, for example, the ring. Circular warrants to the original end-user purchaser that the Circular product is free from defects in material and workmanship for one (1) year from the date of purchase. If your local law in effect at the time of purchase requires a warranty period longer than one (1) year, this warranty shall be extended to the extent required by such law. Within the warranty period, Circular shall repair or replace at no charge to you any components of the Circular product that fail the limited warranty provided. You shall be responsible for any related transportation charges. Replacement products may be new or refurbished at our discretion. This limited warranty does not apply to (i) normal wear and tear, including scratches and dents; (ii) consumable parts included in the Circular product, such as batteries, unless product damage has occurred due to a defect in materials or workmanship; (iii) damage resulting from your failure to use the Circular product in accordance with the instructions accompanying the Circular product or available at the website; (iv) damage resulting from an accident, flood, fire, misuse, or abuse; (v) damage resulting from service performed, or damage resulting from tampering or alterations to the Circular product, by anyone not authorized by Circular; or (vi) use of the Circular product with any other application or software than the mobile app.
Circular retains the exclusive right to repair or replace the Circular product, or offer a full refund, at its sole discretion. Such remedy shall be your sole and exclusive remedy for any breach of warranty. Warranty repairs and replacements have a new warranty which is the longer of ninety (90) days or the balance of the original one (1) year warranty.
In no event will Circular or any of its affiliates be liable for direct, indirect, incidental, punitive, or consequential damages (including without limitation those resulting from lost profits, lost data, or business interruption) arising out of the use, inability to use, or the results of the use of the Circular services, whether such damages are based on warranty, contract, tort or any other legal theory and whether or not Circular has been advised of the possibility of such damages. The aggregate liability of Circular, arising from or relating to the Circular services (regardless of the form of action or claim, e.g. Contract, warranty, tort, strict liability, negligence, or any other legal theory) is limited to €100. Circular's affiliates, providers, and partners have no liability whatsoever arising from the website. In some locations, applicable law may not allow certain of the limitations described above, in which case such limitations will apply to the maximum extent allowed by such applicable law.
Your use of the Circular products and services is subject to our Terms of Use, available at circular.xyz/terms-of-use, and Privacy Policy available at circular.xyz/privacy-policy.
Circular logo © and Circular™ Circular Be More™ are trademarks or registered trademarks of Circular and may not be used without permission. Patented and patents pending. All rights reserved. You are not granted, by implication or otherwise, any license or right to use any marks appearing on Circular Services. One or more patents owned by Circular (or patents licensed from third parties) apply to the Circular Products and to the features and services accessible via the Circular Services maintained by Circular.
Manufactured by Circular.
Circular has not approved any changes or modifications to this device by the user. Any changes or modifications could void the user's authority to operate equipment.
WARNING: This product may contain chemicals known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
This device complies with FCC part 15 FCC Rules. Operation is subject to the following two conditions:
FCC Warning
Changes or modifications not approved by Circular could void the user's authority to operate the equipment.
Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
This device meets the FCC requirements for RF exposure in public or uncontrolled environments.
FCC ID: 2BOAM-CR2
This product is a radio transmitter and receiver. It's designed not to exceed the emission limits for exposure to radio frequency (RF) energy set by the Federal Communications Commission. This transmitter must not be co-located on operating in conjunction with any other antenna or transmitter.
This device meets the IC requirements for RF exposure in public or uncontrolled environments.
IC Notice to Users in accordance with RSS GEN Issue 5:
This device contains licence-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and Economic Development Canada's licence-exempt RSS(s). Operation is subject to the following two conditions:
IC: 29243-CIRCULAR110.
This class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de classe B est conforme à la norme Canadienne ICES-003.
Declaration of Conformity with Regard to the EU Directive 2014/53/EU
Circular is authorized to apply the CE Mark on CIRCULAR RING, thereby declaring conformity to the essential requirements and other relevant provisions of Directive 2014/53/EU and other applicable Directives.
Frequency range: 2402-2480 MHz
Max output power: 3.29 mW
In order to satisfy the essential requirements of 2014/53/Eu Directive, the radio equipment is compliant with the following standards:
RF spectrum use: EN 300 328
EMC: EN 301 489-1, EN 301 489-17, EN 55032, EN 55035, EN 50566, EN 61000
The conformity assessment procedure of Directive 2014/53/EU has been followed with the involvement of the following Notified Body:
Precise Testing & Certification (Guangdong) Co., Ltd. Building 1, No.6, Tongxin Road, Dongcheng Street, Dongguan, Guangdong, China.
This product is compliant with Directive 2012/19/EU. Please dispose used electrical and electronic equipment (WEEE) according to national laws and regulations with electrical waste. It should not be mixed with general household waste.
This product is compliant with the UK Conformity Assessment Radio Equipment Regulations 2017.
Compliant with the standard R&TTE 99/CE/05 Australia and New Zealand R-NZ
Compliant with Japan's TELEC certification.
MIC: 218-250745
Product Name: Circular Ring 2
Model No.: CR2.
Compliant with UAE's TDRA certification.
ER55406/26
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