https://www.doorbird.com/downloads/datasheet/datasheet_keyfob2_en.pdf
Doorbird Intercom Dual-Frequency RFID Transponder Key Fob A8005, 10 p.
$110.03
(GTIN/EAN: 4260423868960, P/n: 423868960)
125 KHz (EM4100) and 13.56 MHz (MIFARE® DESFire® EV2 8K)
For A1121 IP Access Control Device
For D1812 IP Video Door Station
For D21x IP Video Door Stations and later
Material: ABS, waterproof, black
10 pieces