The RW2i rubber wheel features an internal set screw ideal for designs with space constraints. The 1.1-inch diameter wheel by Solarbotics is made for 3 mm diameter output shafts. These wheels are sold individually, NOT in pairs.
This ball caster uses a 1″ diameter plastic ball and has an overall height of 1.1″ (29 mm). The two-part housing snaps together to securely enclose the ball and three plastic rollers that reduce the friction between the ball and the ABS housing. The base piece of the housing has holes for three #4 or M3 screws (not included).