This is a speed sensor, the major goal is to check the rate of motor. It was widely used in motor speed detection, pulse count, the position limit, etc. Features: Groove type optical coupling sensor the output state light, lamp output level, the output low level light. covered, output high level;Without sunscreen, the output low level. the comparator output signal is clean, good waveform, driving ability is strong, for more than 15 ma. has a fixed bolt hole, convenient installation Specification: Groove width 10 mm. the working voltage of 3.3 V to 5 V output form: digital switch output (0 and 1) PCB size: 2.3 cmx2cm use the LM393 wide voltage comparator For any technical support or suggestion, please kindly go to our forum.