The body of microcrystalline zirconium ceramics, the whole body of R4 is made of microcrystalline zirconium ceramics, with excellent refractive index and dispersion performance, so that the whole emits a unique round luster.The newly designed circuit structure greatly reduces the electric field interference between the modules.Compared with the previous generation products, it has increased the sending and receiving distance by 3 times and is easily compatible with various card readers.From 125KH to 13.56MHz frequency band, R4 can simulate a variety of format standard encrypted C card or D card, helping you effectively deal with card swiping scenarios in all fields.Suitable for with a circumference of 62.8 mm R4 is a multi-functional RFID wireless radio frequency ring.The built-in IC and ID modules can be used to replace radio frequency cards such as access cards, parking cards, membership cards, consumer cards, etc.; the built-in NFC module can be used to implement virtual incoming calls, location notifications, Special cloud services such as business card sharing and memo sharing.Applicable people: children Wearing style: wrist strap Applicable system: iOS, Compatible platforms: iOS, Colour: black Material: ceramic metal Size: 7cm x 7cm x 3cm Package Contents: 1 x Smart ring Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/- 1-3cm.