app controlled gas alarm

System Sensor smoke detector alternative — Wanlin, 12-year Chinese smart fire detector manufacturer, WL-SM600 (4G Smart Photoelectric Smoke Detector) certified UL/CE/EN54. Dual-Wavelength Photoelectric + 4G LTE Cat.1 + IoT Cloud + 85dB Siren + 10-Year Battery. 10-year battery, 4G/NB-IoT/LoRaWAN, OEM/ODM from 500 units, factory direct pricing 50-70% below We···