This card works the same as the normal IC cards, for 1K S50 standard. Only the Sector 0 Block Zero which is known as the Serial Number/Manufacturers Block(Chip CUID) could be programmed to any UID you want. CUID card block 0 (UID's block) can be modified arbitrarily. block 0 directly with normal mif read-write device modification. Frequency: 13.56 MHz Capacity: 1k bytes EEPROM memory Rewrite Times: 100,000 times Read Distance: 0 ~ 10 cm(depends on the Reader) Initial Key: FFFFFFFFFFFF (12F) common 13.56 mhz rfid reader writer and nfc phone can not write the particular cards! Colour:random color , don't accept the specified color Material:ABS Package Contents: 10 x CUID Tags Only 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.