Function: waterproof, anti-vibration, anti-corrosion. The outer shell is made of high quality material and does not rust. Simple and convenient operation, Small size, buckle, portable. Application scope: access control system; biometric tracking and identification system; warehousing logistics system; security patrol system; hotel, community card system; identification system security patrol, sauna bath door lock, electronic door lock, access control intercom, bank, Communication, railway transportation, transportation and many other fields; electronic wallets, smart water and electricity meter reading systems and many other industries. Memory:64Bits. Chip:RW1990 Work Type: R/W and encrypt Model: RW1990 iButton Model Number: RFID Key Tag color:Black Material:ABS+stainless steel Package Contents: 30 x Rw1990 TM Key Card Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.