fire door alarm for school

fire door device law direct from Wanlin Fire Protection — 12-year factory experience, WL-FD104 fully certified EN 1155/NFPA 80/CE/FCC/RoHS/REACH. Key specs: RF 433MHz + 4G LTE Backup, Magnetic Reed Switch + RF Wireless, 5-year replaceable battery (2x D lithium). MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Serving 60+ countries acros···