The FS-FENIX03-S4G is a next-generation standalone access controller that combines robust local operation with the power of cellular connectivity. Designed for remote, off-grid, or infrastructure - limited environments, it supports up to 20,000 users and stores 100,000 events locally - ensuring reliable, uninterrupted access control even without a fixed network. Integrated 4G Module: Enables global cellular connectivity for remote management, notifications, and credential updates - no Wi-Fi or Ethernet required. Open-by-Call feature: Authorized users can unlock doors simply by calling the unit’s SIM-enabled phone number- no app or physical keyfob needed. Phone-to-Wiegand Converter: Incoming call events (including caller ID) are seamlessly converted to standard Wiegand 26/34 output.