CIRCULAR startup guide

Welcome! Your journey to better
health starts here.

This startup guide will take you through all the steps to setup your Circular ring and App.

01. getting started

Setup your Circular ring with your charger.

Charge your ring

You first need to wake it up by placing it on the charger and charge your ring to 100% for at least 45 minutes for battery calibration purpose. To do so, you need to take out the charger and place both magnetic pins on those located on your ring.

Understand charging

You can plug the charger into a power source (laptop, power bank, phone...). The connector needs to be USB-C.

Look out for the charger's LED

The LED of the charger will fade in and out when the ring is charging and the LED will turn off when the battery of the ring is full.

02. APP and use

Start using your Circular Ring

Install the app

Search for "Circular ring" on the App Store or Google Play. Once dowloaded, follow the instructions to create an account and to pair your ring!

Wear the ring 24/7 & synch your data

Once you have a ring paired with your account, you are all set! The ring will automatically start tracking your metrics as soon as it detects that you are wearing it. Don't forget that the ring is water resistant, suitable for rain, hand washing and showering.

To see your data in the app, make sure that a sync between the ring and the app has been done. You will see a loading bar appear 5 seconds after you connect to your ring. If it is not the case you can force a synchronization by swiping down on the home page.

03. wear instructions

How to wear your ring

You can wear Circular on any finger except the thumb. 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. But you can still wear it on your little finger.
The flat part of the ring should be
towards the palmar side of your hand
(bottom of your finger). 
The button of the ring should be accessible
with the thumb of your same hand.
To remove your ring

In case the ring gets stuck on your finger:

1. Push the bottom of your ring towards your finger, it should create a space above your finger, between your finger and your ring. Then pull the ring to take it out while continuing pressing your ring towards your finger.

2. Use cold water with soap or gel and slowly twist the ring to remove it.

3. Hold your hand up above your heart until the blood pressure lowers and then try to remove your ring.

Watch out, finger size can vary through the day, your fingers may swell in the morning or evening!
04. CARE

Care and maintenance

Water resistance

Do not submerged the ring under water for prolonged time.

Water resistance

Do not submerged the ring under water for prolonged time.


In order to clean your ring, use a soft cloth or hand wash with mild soap and water.

It is not recommended to 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.


Keep the ring away from children. Do not leave the ring exposed to prolonged heat, such as in a vehicle under the sun.

Scratch resistance

The Circular changeable Outer-shells may get scratches against harder metal jewelry or other objects made of harder materials in contact with.

Electricity safety

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.

Other recommendations

It is not recommended to use the ring when carrying weight. Damage may occur to the ring and button.

The button must be pressed with human fingers only.

Determining your current battery level 

Calibration of the battery percentage level

Charge your ring to 100% for at least 60 minutes when you receive it for battery calibration. Without that, the app may show incorrect battery level.

My ring has reached 0% battery

If your ring has reached 0% battery, please connect the app to your ring before wearing it. If you don't, your ring won't acquire data.

Checking the ring battery level when I wear the ring

By logging into your Circular app and looking at the top-right corner of the home page. You can also click on it to see the battery percentage level.

Checking the ring battery level when I charge the ring

If your ring is on the charger and is fully charged, the charger LED will be off.

Charging your Circular ring

IMPORTANT NOTE: If your ring has reached 0% battery, please connect to your ring with the app. If you don't do it, your ring won't acquire data.

How to charge my ring

The Circular ring is held magnetically to the charger. To charge your Circular ring: 
1. Place the magnetic contact pins from your Circular ring on the charger’s pins.
2. Plug the charger dongle into a USB-C port on your computer or an adaptor on any plug.
3. If charging works then the led of the charger should blink. Your ring is fully charged when the led stops blinking.

It takes 45 to 60 minutes to fully charge your ring when it is empty.

Some pro tips for charging success 

1. Try placing the ring on the charger first, then plugging in the USB port. If you do not see the LED come on, try lightly moving the ring on the charger. 

2. Try taking the ring off the charger and then putting back. 

3. If you still do not see the LED, try flipping the ring 180 degrees (like spinning a penny, not rotating like a wheel) so the opposite charging contact connects. If you still do not see the LED, try cleaning the contact pins of your charger and your ring using warm water and soap, then drying with a soft cloth.

4. If you still do not see the LED, try a different power source or other adapter/charger.

5. When charging a Circular device using a wall outlet, it is recommended that a premium brand AC adapter should be used. Some off-market adapters will prevent the ring from reaching the charging state. 

6. Charge your ring at room temperature. Avoid charging in your cold car, garage, or a room that is too hot. 

7. After a firmware update, the battery display in your Circular app can be off. To make sure the displayed battery charge is accurate, please fully charge your ring again.

Requirements for Use of the Circular Services

The full Circular experience requires Circular 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.

Support and Questions

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 at

If you can’t find what you are looking for, send us an email to
09. safety

Safety Information

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 yourself or moving said heavier objects.

Keep the ring away from children. This product is not intended for individuals under the age of 18. Seek immediate medical attention if you know or suspect that a child has swallowed the ring. Do not leave the ring exposed to prolonged heat, such as the sun. Do not try to open the ring or puncture the ring or its battery.

You may have yellow or brown marks on your finger where the charging pins of the ring lie. This is due to the use of gel and hot water that rubs off the gold color of the contact pins. These marks are non permanent and will disappear. It occasionnally happens and it is easily removed by washing your hands.

However 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 3 days of not using your Circular product, please contact a dermatologist.
10. warrranty

Warranty Disclaimer

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 for non-European countries. 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 :
- Any use of the Product that is contrary to the usually expected use of the Product and the user guide (;
- Any use of a Product that is contrary to or not explicitly authorized within the recommendations published by Circular on the Product;
- Damage caused by or due to an accident, abuse, misuse, corrosion, flood, fire, earthquake or any other external cause;
- Normal wear and tear of the Product; and more broadly damages that appear after the Products are received and that do not affect the operation of the Products;
- Visible defects and cosmetic damages including scratches;
-       Consumable parts included in the Circular product, such as batteries, unless product damage has occurred due to a defect in materials;
- Damage resulting from the use of another product than those supplied by Circular with the Product including the use of external software or application ;
- Malfunction cause by an attempt to modify the Products;
- A poor maintenance of the Products by the Customer or any third party other than Circular (as non-limited examples: soiling, oxidation, corrosion, rust,...);
- Technical manipulations, including the modification or the repair of the operating system and/or the Products by the Costumer and in case of a repair by any organization that has not previously been approved by Circular; More broadly any modification that hasn’t previously been approved by Circular;
- The fact that Circular's Products and Services operate uninterrupted and error-free.

Circular is not liable for damages resulting from an inability to follow the instructions for use of the Product.

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.
11. liability

Limitation of liability

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.
12. terms

Terms of use

Your use of the Circular products and services is subject to our Terms of Use, available at, and Privacy Policy available at
13. ip

Intellectual Property Rights

Circular logo © and Circular™ are trademarks or registered trademarks of Circular 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.

Regulatory & Safety Notices

USA: Federal Communications Commission (FCC) statement. 

This device complies with FCC part 15 FCC Rules. Operation is subject to the following two conditions: 

1. This device may not cause harmful interference and 

2. This device must accept any interference received, including interference that may cause undesired operation 

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: 

• Reorient or relocate the receiving antenna 
• Increase the separation between the equipment and receiver 
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. 
• Consult the dealer or an experienced radio/TV technician for help. 

This device meets the FCC requirements for RF exposure in public or uncontrolled environments. FCC ID: 2A8NL-CIRCULAR110.

Canada: Industry Canada (IC) statement 

This device meets the IC requirements for RF exposure in public or uncontrolled environments. 

IC Notice to Users in accordance with RSS GEN Issue 3:

This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: 

1. this device may not cause interference, and 
2. this device must accept any interference, including interference that may cause undesired operation of the device IC ID: 29243-CIRCULAR110. 

European Union (EU) 

Declaration of Conformity with Regard to the EU Directive 2014/53/EU 

Circular is authorized to apply the CE Mark on CIRCULAR RING, Model One, thereby declaring conformity to the essential requirements and other relevant provisions of Directive 2014/53/EU and other applicable Directives.

In order to satisfy the essential requirements of 2014/53/ EU Directive, the product is compliant with the following standards:
RF spectrum use:  EN 300 328 v2.2.2
EMC: EN 301 489-1 V2.2.3, EN 301 489-17 V3.2.4, EN 55011:2016/A:2020, EN 61000-6-1:2007
Health & Safety (RED art. 3.1a):  EN 62368-1:2014 + AC:2015 + A11:2017 + IEC 62479:2010

The conformity assessment procedure of Directive 2014/53/EU has been followed with the involvement of the following Notified Body: Intertek

Australia and New Zealand

Compliant with the standard R&TTE 99/CE/05 Australia and New Zealand R-NZ


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.
15. specifications

Specifications for your Circular products

Changeable Outer-shell materials

  • Resistant and high-grade alloy of stainless steel and carbon with high-end coating 

Inner-shell materials

  • Non-allergenic, nonmetallic clinical-grade biocompatible resin

Charger materials

  • High-end polymer 


  • 3 LEDs Oximeter sensor: Infrared, Red, and Green
  • 3-axis accelerometer
  • Digital temperature sensor

Input and Output active component

  • Mechanical push button
  • Vibration motor

Memory Capacity

  • Flash ROM memory (up to 10 days)


  • Rechargeable 24 mAh - 31 mAh Li-Ion battery, non-replaceable.

Battery life

  • Up to 4 days


  • 60 min of charging


  • Bluetooth Low Energy 4.2 to 5.0

Firmware Update

  • Automatic firmware updates via the Circular app. Bluetooth Secure DFU. 


  • Suitable for rain, hand washing and showering.

Ring size & characteristics

  • 8 sizes: from 6 US to 13 US
  • 9 mm large x 2.8 mm wide
  • 5 grams

Operating temperatures

  • Usage: -10°C / 45°C
  • Charging temperature 10°C - 45°C
  • Discharging temperature 20°C - 60°C


  • Bluetooth SIG
  • CE
  • FCC Class B digital device
  • EAC
  • WEEE


  • GDPR & HIIPA compliant
  • Data encryption, secure pairing of the ring and the app


  • Free app on iOS and Android
  • Compatible with  mobile devices that run iOS 11.0 or later, or Android 6.0 or later.