PROXIMITY CARD IDK-02N9 operates in the Mifare standard (13.56 MHz).
Suitable for TTLock, TTHotel devices and VDP series video intercoms
Website of the product manufacturer:
https://www.eura-tech.eu/karta-zblizeniowa-eura-idk-02n9-mifare-1356-mhz,3,21,1936