• Multifunctional RFID Ring: The JAKCOM R4 is a versatile RFID wireless radio frequency ring featuring built-in IC and ID modules to replace access cards, parking cards, membership cards, and other wireless RF cards • NFC Integration: With an integrated NFC module, the R4 offers cloud services such as virtual call alerts, location notifications, business card sharing, and note-sharing • Simplify Access Control: Conveniently replace traditional access cards with the R4 Smart Ring's IC and ID modules, enhancing security and ease of access • Enhanced Connectivity: The NFC capabilities of the R4 enable seamless interaction with various smart devices and services, making it a versatile tool for modern lifestyles • Stylish and Functional: The JAKCOM R4 offers advanced technology with a sleek and stylish design, making it a fashionable accessory for everyday wear Regarding Size Measurement: • Use a non-elastic thread to wrap around your finger snugly. • Slightly tighten the thread; otherwise, the ring size may be too large. • Straighten the thread, measure the length, and choose the size based on the table below: Standard US Sizes - Size 8: 57mm, Size 9: 60mm, Size 10: 62.8mm, Size 11: 66mm, Size 12: 70mm. Specifications: Standard US Sizes (Optional): 8: 57mm, 9: 60mm, 10: 62.8mm, 11: 66mm, 12: 70mm Carrier Frequency: 13.56MHz, 125KHz RFID Range: 1~3cm IC Module Type: UID ID Module Type: T5577 NFC Module Type: Ntag213 Protection Rating: IP68 Operating Temperature: -50°C to +80°C Compatible Systems: iOS, Android Materials: Ceramic + Metal Diameter: About 2.5cm Powered: No battery required Package included: • 1 x Smart Ring • 1 x English Manual • Other items not included