Review on 10PCS OSOYOO Obstacle Avoidance Sensor Kit with IR Transmitting, Receiving Tube, and Photoelectric Switch for Arduino, Raspberry PI 4, 3 Model B - Ideal for Smart Cars and Robots by Bill Wasson

They are finicky to set up and extremely sensitive to natural light, even indirectly. The slightest thing but the light from outside keeps them on. While they relied on pulses of a specific frequency so they only picked up their own output, it only seems to pick up any IR light. They also have a very high bounce rate. When buying, they recognize up to 3 cm. After an hour or two of use, at least 3/10 are degraded and can only see about 0.5 cm.