ELEGOO Stepstick Stepper Motor Driver Module A4988 + Heat Sink for 3D Printer Reprap, CNC Machine or Robotics(Pack of 5) Simple step and direction control interface,Take anti-static measures before you use the A4988 modules in case of short-circuit Five different step resolutions: full-step, half-step, quarter-step, eighth-step, and sixteenth-step. Output drive capacity of up to 35 V and  1.2 A Adjustable current control lets you set the maximum current output with a potentiometer Intelligent chopping control that automatically selects the correct current decay mode (fast decay or slow decay) Over-temperature thermal shutdown, under-voltage lockout, and crossover-current protection