Description The RW1990 chip we use is an imported chip, and its performance is more reliable than other chips. The CMOS microcircuit is essentially an electronic carrier and is the only carrier of 64-bit digital codes. This code is stored in internal non-volatile memory. Data exchange occurs via the 1-Wire protocol, which requires a data pin and a common pin. The microcircuit supports the functionality of the ROM search protocol 1-Wire, making it possible for multiple devices to operate on one bus. This protocol determines the changing conditions of the bus status and time interval during synchronization by controlling the synchronization pulse switching of the device. Data is read and written in order of the least significant bit forward. TM card, also known as touch memory, electronic ke3.5y, stainless steel package su304 Sturdy and durable, never rust or corrode; heat-resistant, resistant to mutations; strong sealing, used for security patrols, sauna door locks, electronic door locks, door intercoms, card systems, identification, banking, communications, Rail transit, transportation and many other fields Package includes: 10* smart cards (random color) Note: 1. Please allow a little error due to manual measurement. Please make sure you don't mind before bidding. 2. Color may vary due to different monitors, please understand. Hello, please pay attention to your delivery address when purchasing products. If your delivery information (such as name, street, house number, doorbell/mailbox without name, etc.) is incorrect, the order will not be delivered correctly.)