Speed Measuring Sensor Counter Motor Test Groove Coupler Module For Arduino

"Speed Measuring Sensor Counter Motor Test Groove Coupler Module For Arduino Feature:   Using imported groove optical coupling sensor, width 5mm. It have the output state light, if output high level, the lights are off. if output low level ,it on. If it covered,it will output high level;otherwise it output low level. Good signal and waveform, with strong driving ability for more than 15mA. The working voltage of 3.3V to 5V. Output: digital switch output (0 and 1). Equipped with a fixed bolt hole, easily install. Small board PCB size: 3.2 cm x 1.4 cm. Use the LM393 wide voltage comparer.