The Circular ring is compatible with most mobile devices that run iOS 11 or later, or Android 6 or later.

No, it will always remain free with the purchase of a Circular ring. The only cost is the one time fee of the ring itself.

The ring first collects the body signals it needs thanks to its biosensors (green, infrared & red optical pulse sensor, 3-axis accelerometer, and temperature sensors). The ring contains a built-in processor that will process the data and send the data by Bluetooth to the Circular mobile app & cloud for analysis. The Circular analysis engine uses machine learning to better understand your habits and offer a personal experience with personalized recommendations to improve your lifestyle.

When your heart beats, your capillaries expand, and contract based on blood volume changes. The optical heart rate sensor (PPG) in your Circular ring flashes its LEDs rapidly on the arteries of your finger’s palm side to detect blood volume changes. Your device calculates the number of times your heart beats per minute (BPM), which is your heart rate.

Circular tracks your sleep thanks to the correlation of the data collected by the PPG sensor, the temperature sensor, and the motion sensor. The biometrics of your body evolve during your sleep and your biometrics are in very specific states at each stage of your sleep. That’s how the ring monitors whether or not you are sleeping and in what sleep stage you are in. Circular tracks many other sleep factors to let you understand your sleep and improve it in the long run.

Yes, Circular tracks heart rate during exercise and many other activities. However accuracy is degraded. In a future software update, your ring will automatically detects the activity you are doing and you will be able to input your activities manually in the in-app calendar.

Circular tracks your heart rate variability (HRV) while you sleep, and during a live spot measurement. It calculates your HRV from the rMSSD, a well-known and validated HRV parameter that provides a good view on your Autonomic Nervous System activity.

It’s so simple that you have nothing to do yourself. There is no on / off button on the ring, it knows when you are wearing it or not and goes into standby by itself if you don't wear it. All you have to do is pair the ring to your account on the Circular app and the ring will start taking data.

Yes, if you prefer to keep Bluetooth off completely, you can enable the ring airplane mode inside your Circular app to cut all radio data transmission from the ring. Circular uses Bluetooth to sync your ring’s data with the app, but the ring doesn’t need to be connected to your phone to collect your biological data. The ring can store data for up to 10 days. Just take your ring out of airplane mode and it will begin syncing all your stored data.

Launch your Circular mobile application. The app will ask you to give it permission to access your Bluetooth and localization and then launch the pairing process. You will no longer have to perform the pairing process in the future. Please note that the ring can be paired to one device at a time but an account can be paired to several rings. Your data is stored on your personal and dedicated account and only you will have access to your data. If you have the same Circular account on several phones, you will be able to see your data on these several phones but without being able to synchronize your ring's data on the different phones. Your ring can only sync to one phone at a time.

It is not recommended to use the ring when carrying weight. Damage may occur to the ring and button. It is recommended to wear a special outer-shell for sports as it will scratch faster. Like regular jewelry, Circular can scratch if worn while lifting weights or gripping bars, or when scraping against metal, ceramics or stone. Apart from carrying weight, you can do sports with your ring.

The Circular Pro is water resistant. It's suitable for light water exposure like rain, washing your hands or showering. Do not put the ring under water for prolonged time (bath, sea, hammam).

The Circular Slim is waterproof and is IPX8 grade. The ring can be immersed in 5 meters of water for a maximum of 30 minutes. It is not recommended for use in salted water.

Yes, the ring is waterproof - perfect for washing your hands, showering, or even going for a swim (5m deep).

The ring has a built-in memory of 10 days which means that if your phone is not available, it can collect and store your biometrics for up to 10 days. Past this time without synchronization with your smartphone, the data storage will happen as a First In First Out pattern, which means that the new days of data will overwrite the oldest ones.