A microwarp drive (or MWD) is a module that provides a very large speed boost to a ship, in return for a heavy drain on the capacity of its capacitor. In addition, the microwarp drive consumes a large amount of capacitor when it is in use. It also has a penalty to signature radius meaning that you will be easier to target and missiles will cause more damage (if you signature radius was already smaller than the missiles explosive radius). The MWD will also allow you to thwart a Web / Stasis field.