fire door hold open alarm closing reminder device

fire door alarm for container home direct from Wanlin Fire Protection — 12-year factory experience, WL-FD101 fully certified EN 1155/NFPA 80/CE/FCC/RoHS/REACH. Key specs: WiFi 6 + Bluetooth 5.2, Wireless Position Sensor + Digital Display, 3-year replaceable lithium battery (2x CR123A). MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Se···