The anti-roll bar is normally a U-shaped round bar, 10 to 60 millimetres in diameter. The middle section of the 'U' is attached crossways to the car body on pivoting rubber mounts with the ends joined to the suspension. Lever forces on one side act to balance the opposite side. Anti-roll bars improve tracking (the alignment of the car's wheels), and therefore handling. At the same time, they also reduce body roll. The improved tracking makes cornering safer and more comfortable.