This ball caster kit includes a two-part black ABS housing, a 1″ diameter POM (also know as acetal or by the brand name Delrin) plastic ball, three 3×7×3mm ball bearings, and three dowel pins used to hold the ball bearings. When assembled, the ball caster is capable of rolling in any direction with low friction, making it suitable for use as a third contact point for wheeled, differential-drive robots weighing up to around ten pounds.
The base piece of the housing has holes for three #4 or M3 mounting screws (not included) and slots for ball bearings. The second part of the housing snaps into the base piece to secure the ball and ball bearings. The assembled ball caster has an overall height of 1.1″ (29 mm).