Berdan: TK4100/TK4101, fully compatible with EM4102 Working frequency: 125KHz Working pattern: Read-only Induction distance: 2~10cm Internal serial number: 5 bytes Size: 85.5×54×1.80mm (with a portable hole) R/W range: 2~ 10 cm, depending on the reader and the application environment Working temperature: -20℃ ~ + 80 (-4℉~+176℉) Materials: ABS Wipe times: >100,000 times Data storage: 10 sal