fire door auto release alarm

fire door closing device certification direct from Wanlin Fire Protection — 12-year factory experience, WL-FD102 fully certified EN 1155/NFPA 80/CE/FCC/RoHS/REACH. Key specs: Dry Contact + 4G LTE Backup, Electromagnetic Hold-Open + Fire Signal Release, AC 230V/24V powered + 72h backup battery. MOQ 100 units, 25-30 working days, OEM/ODM custom branding availa···