The reason there are 3 different sizes is because Scalextric does not make all cars the same in regards to the guide area.
Each model of Scalextric cars may take a different thickness B-Nova adaptor. While I understand you're not wanting to buy 12 to use 4, we really can't advise which to buy because we don't know what cars you're working with, or what guide height you're looking for (different people set guides at different heights).
Each model of Scalextric cars may take a different thickness B-Nova adaptor. While I understand you're not wanting to buy 12 to use 4, we really can't advise which to buy because we don't know what cars you're working with, or what guide height you're looking for (different people set guides at different heights).
