... temperature: -25 ° C~ + 70 ° C Introduction To Silica gel wrist watch card:(1) Features: waterproof, moistureproof, shock; And high temperature resistant ... .(2) The closed-loop type wrist strap, elastic, easy to wear and easy to use.(3 ... (125 KHz) high frequency chip (13.56 MHz) encapsulates the watch.(5) The chip: EM4200, EM4305, TK4100, T5557, Mifare1 S50, ...