ADIY NE555 Pulse Frequency Module

ADIY NE555 Pulse Frequency Duty Cycle Adjustable Module Square Wave Signal Generator is 5 V square wave signal generator. It generates a square wave signal used for experimental development. Also, use to drive a stepper motor for generating a square wave drive signal. 

The output duty cycle can fine-tune. Duty cycle and frequency is not separately adjustable, adjusting the duty cycle will change the frequency.