Chip: EM4102, TK4100, TK4101 COB Frequency: 125KHz Work mode: read-only Induction distance: 8~20cm Internal serial code: 5 bytes Wipe: >100,000 times Data storage: 10 years Material: ABS Size: 85.5x54mm Thickness: 1.8mm Working temperature: -20°C ~ +80°C (-4℉~+176℉)