This small roller is a perfect third point for a small, differential drive robot. Using a ball caster provides better performance than just having a part of the robot scrape the ground. And, unlike regular caster wheels, a ball caster will not override your drive motors and steer your robot off course. This unit is made entirely of plastic and is therefore very light.

Dimensions:

-overall height: 20,5 mm

-lower part height(ball-mounting plate): 11 mm

-mounting hole diameter: 9,5 mm