A4988 control board widely used in 3D printers and small CNC machines Simple step and direction control interface Thermal protection, overcurrent protection, ground fault protection Resolutions in five different stages: full stage, half step, quarter step, eighth step and sixteenth stepAdjustable current control allows you to set the maximum current output with a potentiometer, allowing you to use voltages higher than the rated voltage of your stepper motor to achieve higher step speedsFeatures:Size:A4988: 20*15*11mm (LWH)Heat sink: 9*9*5mm (LWH)Weight: 0.8ounces Color: Red Features: - Intelligent hash control that automatically selects the correct current decay mode (fast or slow decay) - Thermal shutdown against overheating, undervoltage lockout and cross current protection - Auto detection/selection of current decay mode - Internal UVLO - Mixed with slow current decay modes - Synchronous rectification for low power dissipation Overcurrent protection Thermal cut-off circuit Compatible logic supply -3, 3 and 5 V Thermal cut-off circuit Fault circuit at the ground Load short circuit protection - Five modes optional: full, 1/2, 1/4, 1/8 and 1/16 Package included: A4988 stepper motor plunger module 5 * 5 * heat sinkNote: The data are all manual measurements, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, depending on the object physical received.