The (6 inch) **2mm Omni-directional wheels are unique as
they are able to roll freely in two directions. The Omni-direction
wheels allow a robot to convert from a non-holonomic to a holonomic
robot. A non-holonomic robot that uses normal wheels has only 2 out
of 3 controllable degrees-of-freedom - moving forward/backwards and
rotation. Not being able to move side ways makes a robot slower and
less efficient in reaching its given goal.
