100Pcs Readable RFID Tokens 125Khz EM4100 Tags ID Card Key Chain Card Access RedSpecifics: 100% Brand New and High Quality. Shape: Same as the picture show 1. The chipset is TK4100 2. this keyfobs can't writable,just can read only,it has unique ID number. 3. Each token pre programmed with unique ID which is printed on it 4. Each comes with Key ring included 5. Compatible with all RFID reader to gain access 6. No external power required. 7. Brand new key inductive card for entrance guard system. 8. Easy to carry 9. Water resistant