User Guide

5
Bluetooth Low Energy 4.2 to 5.0. Encrypted communication is used between the
ring and the app and the between the app and the cloud servers.
Firmware Update
Automatic firmware updates via the Circular app. Bluetooth Secure DFU.
Waterproof
● The ring is water resistant.
● The charger is not waterproof and is intended for indoor use only. Do not use
or store the charger in humid environments.
Ring size & characteristics
● 8 sizes: from 6 US to 13 US
● 9 mm large x 2.75 mm wide
● 4-5 grams
Operating temperature
-10°C / 45°C
● charging temperature 10°C - 45°C
● discharging temperature 20°C - 60°C
Charger input connector and voltage
● USB Type-C connector 5V
● If you use an extension cable to charge the ring, please use the one sold on
the Circular website.
● The charger shall be supplied by a power source that shall meet the standard
for limited power supply.
Certifications
● Bluetooth SIG
● CE
● FCC part 15 Class B digital device
● IC
● UKCA
● RCM
● ROHS