The QTR-HD-01A Reflectance Sensor is a high-resolution reflectance sensor made by Pololu Robotics and Electronics—a leader in robotics automation and components. This reflectance sensor has three visible-light LEDs, one infrared LED and one photodetector in each white plastic package with a 0.69"x0.7" (1.75cmx1.78cm) footprint.The QTR-HD-01A can measure the reflectance of colors, shapes and sizes with accuracy and resolution far rivaling expensive commercial labs and systems. The sensor offers a wide range of options for settings, allowing it to be configured for various applications. It can be used for low and high resolution sensing, vector maintenance and detection, surface and size estimation and other similar tasks.The distinct PCB design, with its hinged mounting holes, allows for tweaking and adjustment to cater to specific tasks in real time. Not only does the QTR-HD-01A offer higher sensitivity and accuracy than other competitor’s similar products, its dimensions are also more compact, allowing for easy integration into a variety of systems.