We provide 24-hour after-sales service. If there is a problem with the product,or you can't operate it. Please do not hesitate to contact us. Smart Ring Size: No.8 (Perimeter 57.1 mm), No.9 (Perimeter 60 mm), No.10 (Perimeter 62.8 mm),No.11 (Perimeter 66 mm),No.12 (Perimeter 70 mm),it does not require battery charging , it has IP68 grade waterproof and dustproof,it is anti-abrasive, no fading, no deforming,suitable for all occasions. CatXQ Smart Ring Compatible with IOS (XS,XR,XS Max,11 series,12 series,13 series) and Android,. CatXQ Smart Ring:The Built-in NFC module can realize virtual call,Scene notification,Business card sharing,Memo sharing and other featured cloud services. CatXQ Smart Ring:Built-in IC and ID modules,4 smart cards can be simulated at the same time (Access Card,Elevator Card,Time card,Parking Card,Membership Card,Shopping Card and Other RFID Cards),the read-write process of ic/id card module is the same as ordinary cards.within the sensing range of the ic/id module,it can be authorized or copied by the corresponding dedicated read-write devicel.Date First Available: March 9, 2022. Best Sellers Rank: #112,720 in Electronics. Customer Reviews: 2.5 out of 5 stars 18 ratings 2.5 out of 5 stars. Item model number: CatSmaR05. : B09V5D1428. Manufacturer: JAKCOM. Item Weight: 1.44 ounces. Package Dimensions: 3.43 x 2.76 x 0.94 inches.