This is a collection of emission and reception in one photoelectric sensor. Detection distance can be adjusted according to requirements. The sensor has a detection range, interference by visible light small, easy to assemble, easy to use and so on. Can be widely used in robot obstacle avoidance, assembly line and many other automated products. Photoelectric sensor (photoelectric switch) NPN normally open. Colour:As shown Material:Plastic + Metal Package Contents: 3 * E18-D80NK Infrared Photoelectric Switch Obstacle Avoidance Sensor Module Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.