Bluetooth fire door device

fire door closing visual alert direct from Wanlin Fire Protection — 12-year factory experience, WL-FD105 fully certified EN 1155/NFPA 80/CE/FCC/RoHS/REACH. Key specs: 4G LTE Cat.4 + Ethernet + WiFi, Multi-Door Network + Cloud Management, Gateway AC powered + 48h backup; sensors battery-powered. MOQ 100 units, 25-30 working days, OEM/ODM custom branding avai···