Features: 3P 2.54mm pin header. Output terminal of the output square waves signal, the amplitude is approximately equal to input voltage. Output duty cycle is not adjustable, basic stability of duty cycle of the output signal in the process of adjusting the frequency (50% -65%). Frequency through built-in multi-turn potentiometer adjustment, adjustment range: L version is 0.8Hz-60Hz;H Verson is 50Hz-6kHz The output circuit is capable of sinking or sourcing current up to 200mA. Clockwise adjustment potentiometer, frequency increases, adjustment potentiometer counterclockwise, frequency decreases.