This is a hollow version of a 30mm shifter knob for car themed pinball games. It is hollowed out to purely reduce the weight and cost of the design. It isn't the cheapest but would look dam nice in a game. it has a 10.2mm hole that you can glue in the shooter rod (that is available from Pinball Life) with epoxy glue, set and then install for a cool unique look. To personalise it you could paint in the gear shift pattern.