Kyosho ST-2 Rubber Wheel/Cone? (Maybe for a starter?)

Kyosho ST-2 Rubber Wheel/Cone? (Maybe for a starter?)

Not sure what this is. Looks like in might be for a starter. 55mm diameter at the widest end with an 18mm diameter hole. The narrower end is approx 40mm with an approx 35mm hole (seems to taper to the wide end)