installation date smoke detector

fault alarm smoke alarm direct from Wanlin Fire Protection — 12-year factory experience, WL-SM605 4G standalone smoke detector certified CCCF/GB 20517-2006/CE/UL 217/EN 14604. Key specs: Dual Light Path Photoelectric + LoRaWAN Long Range + Maze Sensor + Low Power, LoRaWAN + IoT Gateway + Cloud Platform + Long Range (up to 15km) + Battery Optimized. Dual lig···