Product Description Smoke detection sensor system with alarm is designed to detect the smoke, Which helps to protect your house property from being damaged by fire. After installed unit it will working state the LED will flash one time a minute, when some smoke modes are detected, It will give out ringing & loud Whistle until the are density in balance. Smoke sensor is easy to install and maintain. Mount it on the ceiling and the system will operate off a 9 Volt battery. When fire occurs, smoke particles enter this sensor and trigger a reaction that causes the LED light to flash rapidly. It has a high stability and sensitivity over low power supply voltage conditions. It can also detect smoke with medium density. The alarm provides high reliability in harsh environments by using high quality components. The product has high reliability and practicability, with simple structure, convenient installation, easy to operate and maintain. Specifications Operating temperature: - 10 to +50 °C Ambient humidity: < 95% Dimensions: Ø 102 x 38 mm Weight: 85 g Red LED