Features: The R18 intelligent rings combines advanced health monitoring features including 24/7 heart rate tracking, step counting, and calorie expenditure measurement in a lightweight wearable, perfect for fitness enthusiasts seek comprehensive activity insight. This unisex intelligent rings offers three adjustable size (6,10,12) for secure, comfortable wear during workouts or daily use. Ideal for gym enthusiasts, health professional, this fitness trackers seamlessly integrates into active lifestyles while maintaining a jewelry like appearance. Monitor real time heart rate during HIIT, track sleep pattern overnight, and analyze step goal throughout workdays, all while wearing this water resistant intelligent rings that syncs effortlessly with companion health apps. With its scratch resistant finish, the R18 delivers clinical level health data for optimizing workout routines and sleep quality, making it a various companion for holistic wellness management. Specifications: Product name: Intelligent Rings size: No. 6: Inner diameter: 16.5mm Peripheries: 51.8mm No. 8: Inner diameter: 18.1mm Peripheries: 56.9mm No. 10: Inner diameter: 19.8mm Peripheries: 62.1mm No. 12: Inner diameter: 21.4mm Peripheries: 67.2mm property: No. 6, 10, 12 Package Includes: 1pcs Fitness Rings note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.