This board is a drop-in replacement for the A4988 Pololu board. It is superior in that it can handle 1.5A instead of 1A without extra cooling, and rated upto 2.2A with a heatsink and fan. It also has microstepping resolutions down to 1/32 microsteps (instead of 1/16th)
Comes with a header strip which needs to be soldered on for mounting to a RAMPS shield, but is left off so you have the option of using it in a different way, such as attaching to a ribbon cable or breadboard.
Supplied without a heatsink (available seperately).

These tiny boards provide the electrical pulses needed to get a stepper motor to move, under instruction from the RAMPS board. Compatible with RAMPS 1.4 boards, which need 4 or 5 of these. Provided with headers already soldered and a heat sink

These tiny boards provide the electrical pulses needed to get a stepper motor to move, under instruction from the RAMPS board. Compatible with RAMPS 1.4 boards, which need 4 of these. Provided in kit form with header strips (you need to solder them) and now with a heat sink.
Capable of Full to 1/16th microstepping. Power input from 8-35V with logic voltage of 3-5.5V. Four, six, and eight-wire stepper motors can be driven if properly connected. Click More Info for full details at the Pololu website.
These are not compatable with the Makerbot or MBot motherboards as the MS3 pin on these boards is used for a different purpose (VR - Reference Voltage) on the Mightyboards.

This fully assembled Board includes the processor, memory and interfaces you can use of a variety of projects

Buy the major electronics componants of a 3D printer together in this sandwich kit. No soldering required