Features: Achieve precise control with adjustable pulse frequency (Hz to hundreds) and 0- 100 duty cycle via potentiometers, delivering stable squares waves signals for steppers motor driver and PWM applications. Powereds by NE555 chip with 5V-15V wide input ranges (15-35mA output), ensures integration into electronics projects while maintaining waveforms stability. for electronics enthusiasts, engineers, and maker requiring customizable signals outputs for prototyping, automation systems, or educational STEM/robotics experiments. Use in motor speed regulation, LED dimmers, relays timing circuits, sound synthesizers, or industrial equipment testing where adjustable frequency/duty cycle signals. two knob interfaces simplifies realtime adjustments, while construction supports repetitive laboratory for ecosystems. Specifications: Size: 3.1x2.2cm/1.22x0.87inch Quantity: 2Pcs, 4Pcs(optional) Package Includes: 2/4Pcs Stepping Motor Driver note: Please allow 0-1cm error due to manual measurement. make sure you not mind before bid. Due to the differences between different monitors, the picture may not reflect the actual of the item.