This ball caster kit includes a black ABS housing, a 1/2" diameter plastic ball, two spacers
(1/16" and 1/8" thick), and three #2 screw sets.
The total height of this ball caster is 1.1" with no spacers. You can also adjust the height by adding the spacers.
The ball caster can be mounted to a chassis by the three screw sets included in the kit. The distance
between the two screw holes is 0.70".