This item is a pair of Active Infrared . Install each pair at the opposite positions at . Then there will be a infrared area between these two parts. When someone enter into the infrared region, the will send alarm to the security alarm host. And then the security alarm will give an alarm. Feature - Color: Black - Material: PC - Single Alarm Size: 9x7.5x17cm - Outdoor guard distance: 100m. - Beam Quantity: 2 - Light Source: Infrared - Current: 65mA - Working Temperature: -25 °C -65 °C - Working Humidity: 95% - In the shape of cylinder, it is comfortable to grip and easy to install. - Dual infrared beam transmitter and receiver, more accurate and efficient. - Adopting advanced technology, it has strong resistance to hard light and bad weather. - Equipped with 3 indicators, easily understand the pairing status. - Working parts are angle adjustable, can pair them more easily and there will be less effect of restriction of . Package list: 1 x pair of Infrared Sensor