Specially modified high-performance 3mm-wide drive belt is 1mm narrower than original 4mm belt (#305441) for increased transmission efficiency. This belt is very thin and elastic as possible for an extremely effective transmission that saves batteries and eliminates friction. The belt is specially modified - hand ground on a special machine so the belt is as thin as possible, but in such a way that it will still have long life.

To fully enjoy the benefits from these high-performance belts, be sure all the transmission's ball-bearings are absolutely clean and there is no undue drag or friction.