Feature: 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. Package List: 1 x Smoke Sensation1 x Terminal Line2 x Screws2 x Expansion Tubes1 x User Manual