Makeblock Me RGB Line Follower V1 is specially designed for line detect competition. It contains 4 RGB fill flashes and 4 photodiodes. This sensor can be used to detect line on deep background with light color track and light background deep color track as well. (Support for mBot) Support Arduino IDE programming, and supply runtime library to simplify programming It has 4 LED which are used to line detect feedback and new environment learning Used RJ25 port which can connect easily Suitable for Makeblock DIY platform metal parts: the white area on the sensor can contact with metal parts Technical Specifications Item Dimensions: 48 x 72 x 26.5 mm Item Weight: 15.90 g Operating Voltage: 5V DC Detecting Height: As the differences of material and light condition of the track, it is advised that the distance between probe and track is from 5mm to 15mm Operating Temperature: 0°C ~ 70°C Signal Mode: I2C communication (blue and white colour code)