Motion Sensor Photocell Garage Door Infrared Sensor 12V-24V AC/DC For Sliding Gate Ir Barrier Product introduction： Install each pair at the opposite positions.Then there is a infrared area between these two detector parts. When someone passes the infrared region, the detector will send alarm signal to the security alarm host (which not included here). Install Distance(Max.)in the above chart means the maximum install distance between the two detector parts. When interrupt the infrared, the relay will output switch signal, it can work for parking barrier, walking gate, vehicle gate as body induction. It also can work as window, door and passageway anti-burglar detection. Great to be installed for security system in school, office building, hospital, home yard, etc. Detecting range can be reduced to 30% in bad weather conditions, like rain, dust, etc. English Usage Manual included in the pack. It will give you detailed instructions. Technical Parameters Detector Area: indoor 20m. Outdoor 10m work voltage:12V,24V DC ( can NOT working with AC power, the user manual is wrong ) Work current : 50MA temperature : +70~ (-20) Size : 76 x 49.2 x 21.6MM Water Proof, UV proof wide range of uses: Garage doors, Electronic gates, Barrier gates, sliding doors, automatic doors, rolling doors, shutters Electrical appliances/Home automation i.e. lights, Alarm system, access control system _x000D_