PROFESSIONAL DESIGN: Unique design of the Circuit of Digital Filter with High Capacity anti RFI / EMI. Optical antiinterferencia Housing Professional. Function of frequency adjustment of four channels, suitable for the installation of pile in the same place. SCOPE OF APPLICATION: Widely used for Alarm System, Access Control System, etc. Can be installed in schools, office buildings, hospitals, families, hotels, etc. Excellent quality: Made of high quality plastic shell, eco-friendly, durable and sturdy to use.The plastic case 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. Receiving a long range: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 alarm within the range of 20 meters. Weather instructions:Therefore, the infrared detector still has the ability to detect the distance when it is used in inclement weather.Range can be reduced to 30% in bad weather conditions: fog, rain, dust, etc.