The body of microcrystalline zirconium , the whole body of R4 is made of microcrystalline zirconium , with excellent refractive index and dispersion performance, so that the whole emits a unique round .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 and is easily compatible with card .From 125KH to 13.56MHz frequency band, R4 can a 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 mmR4 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 such as business card sharing and memo sharing.Applicable people: childrenWearing style: wrist strapApplicable system: iOS, AndroidCompatible platforms: iOS, AndroidColour: blackMaterial: ceramic + metalSize: Diameter: about 2.5cmPackage Contents:1 x Smart ringOnly the above package content, other products are not included.Note: Light reflection 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.