heat detector for subway tunnel

temperature sensor for factory direct from Wanlin Fire Protection — 12-year factory experience, WL-HD908 fully certified UL 521/EN 54-5/CE/FCC/RoHS/REACH. Key specs: 4G LTE Cat.4 + WiFi 6 + Matter, Heat + Humidity + Temperature Multi-Sensor Array, AC powered + 72h backup battery. MOQ 100 units, 25-30 working days, OEM/ODM custom branding available. Serving ···