Catalog > Consumer Electronics > Kits > Smart Kits EM4100 Proximity Smart Tag EM4100 Smart Proximity Tag HKD RFID KEY 125KHZ - 5/PKT EM4100 CHIP , 125KHZ RFID KEY FOB PASSIVE , PROXIMITY SMART TAG . Call for Price 0 in Stock Add Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Overview 125Khz Door Keeper keys, EM4100 Standard protocol, only read, can not write. Available in random colors. Use it together with 125Khz EM4100 RFID Card Read Module RDM630 UART Output Arduino shield. Specifications Technology Type: Key Fob Proximity Smart Card Standard: ISO11785 Frenquency: 125KHZ Chips: EM4100 Power: Passive Card Function: Identification, Payment, Encrypt/DEcrypt Contours: ISO Card Chip Type: Contactless ID Card Application Field: Access Control, Time Attendance