Review on Infrared Reflective Photoelectric Obstacle Avoidance Sensor by HiLetgo by Roberto Manzer

I was very impressed by the device. Each unit was static bagged and sealed and they were all bagged. Before using the blocks I tested each sensor and they all worked. I use them with 4.5V DC and they detect objects at a maximum distance of 10-13 cm. The blocks have an adjustment potentiometer that allows you to change the distance and two LEDs, one to indicate power and the other to light up when an object is detected. I found this useful for fine tuning the sensor. I visually inspected the modules and they all looked well made, especially for the price.