1. 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. 2. NFC Integration: With an integrated NFC module, the R4 offers unique cloud services, including virtual call alerts, location notifications, business card sharing, and note-sharing. 3. Simplify Access Control: Conveniently replace traditional access cards with the R4 Smart Ring's IC and ID modules, enhancing security and ease of access. 4. 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. 5. Stylish and Functional: Not only does the JAKCOM R4 offer cutting-edge technology, but it also boasts a sleek and stylish design, making it a fashionable accessory for everyday wear. 6. 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. 7. 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℃ to +80℃ - Compatible Systems: iOS, Android - Compatible Platforms: iOS, Android - Materials: Ceramic + Metal - Diameter: About 2.5cm - Powered: No Need 8. Package included: - 1 x Smart Ring - 1 x English and Chinese Manual - Other items not included