fire door closing audio reminder

smart diagnostic fire door alarm direct from Wanlin Fire Protection — 12-year factory experience, WL-FD106 fully certified EN 1155/NFPA 80/CE/FCC/RoHS/REACH. Key specs: 4G LTE Cat.4 + WiFi 6 + Zigbee 3.0, AI Adaptive Analysis + Multi-Sensor Fusion, AC powered + 48h backup battery. MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Serving···