R10-AC
The short droid stands roughly half a meter tall, much more compact than it's predecessors.  It has a silver cylindrical body, a rotating dome head, and two primary legs.  A third leg can extend from underneath to offer stability as it rolls.  The two legs are thick and seem to be of a single piece save for the wheels embedded in the bottom.  There are multiple blinking lights, a single large EM sensor on the front as well as a few other sensors, lights, and interfaces embedded in the dome or body.

The thing looks solid, well built, and perhaps on the high end of expense for its day, though now it's value is immeasurable given it's age, individuality, and a host of other factors.