Features: The R13 small rings with Case (Black) revolutionizes wearable , offering real time body temperature monitoring, gesture controlled photography, and 12+ sports type , pair with smooth /APP data synchronization for comprehensive health trackings . Crafted from premium steel, this IP68 rate small rings features electrostatic defense (±6KV contact/±10KV air) and operates flawlessly between 0 45°C, while its crystal charging case ensures safe storage at 10 55°C with overheating defense . Ideal for fitness enthusiasts search advanced sleep analysis (trackings durations /quality) and gamers craving immersive motions controlled interactions, this multiple functional wearable bridge health consciousness with entertainment. From trackings daily step counts during morning runs to monitoring cycles at night, this weather companion excels in gym meeting , business trip, and home gaming environment with 95% humidity tolerance. Combining grade biometric sensors with gesture commands, this small rings redefines wearable convenience through its sweat resistant design, 7 day battery, and platform compatibility with /os system devices. Specifications: Material: steel No.9: Inner diameter 19mm, perimeters 57mm No.10: Inner diameter 19.9mm, perimeters 62.5mm No.11: Inner diameter 20.7mm, perimeters: 65mm No.12: Inner diameter 21.5mm, perimeters 67.5mm Package Includes: 1 set small rings note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the differences between different monitors, the picture may not reflect the actual colorful of the item.