Features: 1.[Wide Application] Suitable for smoke detection in indoor environments such as residences, shopping malls, hotels, restaurants, office buildings, etc. 2.[Wired Networking] The smoke alarm is wired for networking, which can be linked to the building intercom system, security alarm system, etc. 3.[High Sensitivity] Using sophisticated production technology, the smoke alarm has high sensitivity and excellent performance. 4.[Low Power Consumption] Made of high quality materials, the smoke alarm is stable, reliable, durable, and consumes little power. 5.[Sound Light Alarm] Equipped with red LED alarm indicator, has sound and light alarm, has simple operation and convenient use. Specification: Item Type: Smoke Alarm Material: ABS Model: 820 Uses: Suitable for Smoke Detection in Indoor Environments Such As Residences, Shopping Malls, Hotels, Restaurants, Office Buildings, Teaching Buildings, Banks, Libraries, Computer Rooms and Warehouses Working Voltage: DC 9V to 28V Quiescent Current: 70mA Alarm Current: 90mA Alarm Indicator: Red LED Alarm Sound Pressure: 85db/m Working Temperature: -10 to +50 Environmental Humidity: 95%RH (No Condensation) Monitoring Area: 40m2 Alarm Mode: Sound and Light Alarm PackageList: 1 x Smoke Sensation 1 x Terminal Line 2 x Screws 2 x Expansion Tubes 1 x User Manual