This product is a carrier board or breakout board for Allegro’s A4988 DMOS Microstepping Driver with Translator and Overcurrent Protection. This stepper motor driver lets you control one bipolar stepper motor at up to 2 A output current per coil (see the Power Dissipation Considerations section below for more information). Here are some of the driver’s key features:
-Simple step and direction control interface
-Five different step resolutions: full-step, half-step, quarter-step, eighth-step, and sixteenth-step
-Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates
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
Short-to-ground and shorted-load protection
More data:http://www.pololu.com/catalog/product/1182

This article is drop-in replacement for A4983 with additional integrated protection.