1000 pcs waterproof Only Read TM1990A-F5 ibutton with Green holders |

  TM (Touch Memory) uses single-line protocol communication to complete data reading and writing through instant touch. It has the ease of operation of non-contact IC card and the cheapness of contact IC card.       The TM card integrated circuit chip is sealed in a stainless steel case, waterproof, shockproof, anti-corrosive, durable and requires no wiring; The TM card is a passive device that reads information by means of a reading and writing device; Built-in laser engraved 64-bit binary code, the total number of codes can reach 280 trillion; TM card chip has electrostatic protection and uniqueness can not be copied.     Technical indicators:   Average failure: 1/100,000 normal use Manufacturer serial number: the world's only 64-digit number System logic: 64-bit password protection Storage capacity: 8Kbits RAM . Card reading method: touch type Read and write features: readable and writable and encrypted Read and write times: more than 1.5 billion times Operating temperature: -40 °C ~ +85 °C Number of readings: >350,000 times . Service life: >20 years .TM card size: φ16.25mm×5.89mm Product weight: 0.05kg   Unlocking principle: When opening the door, the electronic control system of the lock verifies whether the 64-bit password saved in the TM card is the same as the password held. If you open the door the same, you will not react. If the alarm is triggered when a certain number of digit strings are continuously tried, that is, the TM card has a difference of 64 to the power of 64.         used in intelligent community, postal, railway, fire, electricity, cable TV, chemical, oil and other inspection systems and hotels, school dorms TM door locks, TM water meters, TM meters and TM gas meters.             1000pcs TM1990A-F5 ibutton with green holders.