Designer: Unique design of high capacity digital filter circuit against RFI/EMI. Professional anti-interference optical housing. Four channel frequency adjustment function, suitable for stack installation in the same place. SCOPE OF APPLICATION: Widely used for alarm system, access control, etc. Can be installed in schools, office buildings, hospitals, families, hotels, etc. Excellent quality: Made of high quality plastic shell, environmentally friendly, durable and sturdy for use.The plastic housing has excellent characteristics such as corrosion resistance, easy cleaning and waterproof. When there is no external force, it is generally not destroyed, and the service life is very long. Long range reception: Create a reliable and invisible infrared beam up to 20 meters. By installing the receiver and transmitter at the same level, it can effectively detect and reach the detector within the range of 20 meters. Weather Instructions: Therefore, the infrared detector still has the ability to detect the distance when used in bad weather.Range can be reduced to 30% in bad weather conditions: fog, rain, dust, etc. Feature: Photocell Beam Sensor Color: Black. Material: Plastic. Size: 8x5x4.5cm/3.14x1.96x1.77inch. Technology: Infrared (Photocell). Receiver Range: 65in (20m). The range can be reduced to 30% in bad weather conditions, such as rain, dust, etc. Frequency: 1.92 KHz. Power Supply: 12V to 24V DC/AC. Wavelength: 940nm. Input: 15mA RX - TX 30mA, Angle: