USB Controller Board -A4988 Stepper Driver Module Highlights Generic A4988 Stepper Driver Module Simple step and direction control interface. Five different step resolutions: step, half-step, quarter-step, eighth and sixteenth step. Adjustable current control allows you to set the maximum current output with a potentiometer, allowing you to use voltages higher than your stepper motor's rated voltage to achieve higher stepping frequencies. Intelligent trimming control that automatically selects the correct current decay mode. (rapid decay or slow decay) Overtemperature thermal shutdown, undervoltage blocking and crossover current protection. With exposed heat dissipation plate to improve the heat dissipation function. Package includes: 5pcs A4988 Stepper Motor Driver Module