auditorium smoke alarm

voice alert carbon monoxide alarm — Wanlin, 12-year Chinese smart fire detector manufacturer, WL-SM602 (LoRaWAN Smart Photoelectric Smoke Detector) certified UL/CE/EN54. Photoelectric + LoRaWAN 15km + Ultra-Low Power + 10-Year Battery. 10-year battery, 4G/NB-IoT/LoRaWAN, OEM/ODM from 500 units, factory direct pricing 50-70% below Western brands.