... used in very humid environment, such as swimming pool , cooling library ,waterproof patrol , field operations, also can work properly even ... in water for long time.6. Imitication watch shaped cards containing a contactless ... chip, low frequencey(125KHz) andhigh frequency(13.56MHz)7. RFID chips:EM4100,EM4102,EM4450,TK4100,T5557,Hitag1,Hitag2,HitagS,Mifare1 ...