Specially modified high-performance KeVLA r-reinforced 3mm-wide drive belt is 1mm narrower than the original 4mm belt 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.