Specification Brand : itapring BulletPoint1 : NOTE: They are blank tag with no pre-programmed serial numbers. Before you can use it, you need to write data through a 125khz RFID read/write device in order to read the ID serial number. BulletPoint2 : The chip is readable/writable/rewritable. It can be erased and written 100,000 times. BulletPoint3 : Applications: intelligent door locks, access control systems, time and attendance devices, hotel key cards. BulletPoint4 : Round sticker on the back for attaching to other items (can be attached to metal). BulletPoint5 : Note again that the data cannot be read until the chip is programmed. Color : White Department : unisex-adult ExternallyAssignedProductIdentifier1 : 0798610516126 ExternallyAssignedProductIdentifier2 : 798610516126 FinishType : Glossy ImportDesignation : Imported IncludedComponents : 26 Bit Proximity CR80 Cards ItemName : itapring Anti-Metal Tag Stickers Blank T5577 Rewritable 125Khz RFID Small Coin Round Card for Access Control Systems-10pcs ItemPackageDimensions_Height : 10.7 centimeters ItemPackageDimensions_Length : 0.3 centimeters ItemPackageDimensions_Width : 7.9 centimeters ItemPackageQuantity : 1 ItemShape : Round ItemTypeKeyword : commercial-access-smart-cards Manufacturer : itapring Material : High-grade PVC ModelName : Ky-4-002 ModelNumber : Round-25mm-T5577-3M-Anti-metal NumberOfBoxes : 1 NumberOfItems : 10 NumberOfLabels : 10 NumberOfPieces : 2 PartNumber : Round-25mm-T5577-3M-Anti-metal ProductDescription : Material: High-grade PVC + Sticker + Anti Metal Layer Size: 25mm diameters, 1.2mm of thickness Finish: Glossy Color: White Weight 1g Chip: T5577 Frequency: 125Khz Memory: 363bits Working Method: Read-write Protocol: Configurable for ISO/IEC 11784/785 compatibility Working: Temperature -40 ℃~85℃ Feature Waterproof Reading: Distance 0~10 cm Data Retention: > 10 Years Read-write Times: > 100,000 Times