?This is ID Card Keychain Door Access Control Blue TK4100. It is used in patrol system£¬ attendance systems£¬ access control systems£¬ enterprise systems£¬ radio frequency identification field etc..                                    Features                Small and exquisite appearance£¬ durable£¬ does not fade<br>    You can hang it on the key ring. Very easy to carry<br>    This ID card spray one inner code on its surface<br>    Data storage using EEPROM£¬ the data stored for more than 10 years<br>    A total of 64-bit data storage capacity£¬ including manufacturers£¬ distributors and users of the code<br>    Through special equipment£¬ you can copy the same number ID card<br>    Typical Applications: Patrol system£¬ attendance systems£¬ access control systems£¬ enterprise systems£¬ radio frequency identification field<br>                                                            Specifications                        Chip     TK4100    <br>          Operating Frequency     125KHZ    <br>          Sensing Distance     8 - 20 cm    <br>          Working Temperature     -10 ~ +50&#8451;    <br>          Material     Plastic    <br>          Color     Blue    <br>          Size     2.8 x 3.5 x 0.5 cm / 1.1 x 1.38 x 0.2 inch (L x W x H)    <br>          Weight     5g / 0.18oz    <br>                                                             Package Includes                1 x ID Card Keychain Door Access Control Blue TK4100<br>