1,It is plastic housing with a microchip inside containing a unique serial code which is then related to a check point

2, Anti-destroyed & Waterproof, anti-corrode, fit for every environment

3, Non-contact EM-ID card

4, Long lifetime: >20 years

5, High sensitive and Long inductive distance

6, Wide temperature scope: -40+70

7, Not need power supply

8, Original USA material, warranty: 5 years

9, Dimension: φ35mm, Thickness: 4mm