The dormakaba 12670-DS4-P-BK key fob is a dual-technology credential designed to deliver seamless access across both modern and legacy systems. Featuring secure 13.56MHz MIFARE® DESFire® EV3 4K technology alongside integrated 125kHz proximity capability, this fob allows a single credential to function with smart card readers and traditional prox readers simultaneously. Ideal for mixed-environment deployments, it is commonly used with dormakaba RFID locks, Saflok and Ilco systems, as well as 125kHz access points such as parking gates and perimeter entry. The 12670-DS4-P-BK provides enhanced security through encrypted communication on the DESFire platform while maintaining backward compatibility for existing infrastructure. Durable and compact, this key fob is a practical solution for facilities upgrading to higher-security systems without replacing all legacy readers.