ERICAT Smart Fitness Ring - Intelligent Sleep Monitor IPX-8 Waterproof

This product has 2 sizes to choose from, please confirm the size that suits you before purchasing. Specification: System requirements: Android: 6.0 or above; iOS: 11.0 or above Battery capacity: 23mAh Charging box Capacity: 400mAh Charging time : 1 ± 0.5 hours Size: 18mm/20mm Package Includes: Smart Ring*1 Charging Compartment*1 Charging Cable*1 Notes: Please allow the slight color difference caused by the shooting light and 1-3 cm error due to manual measurement.