3: Frequency through built-in multi-turn potentiometer adjustment, specification:adjustment range: L version is 0.8Hz-60Hz; 1: Output terminal of the output square wave signal, the amplitude is approximately equal to input voltage. 2: Output duty cycle is not adjustable, basic stability of duty cycle of the output signal in the process of adjusting the frequency (50%-65%). 4: 3P 2.54mm Pin header, Weight: 0.00551155655 Pounds, Manufacturer: Jaywool