Speedo cable is unique in the sense that it actually spins around, powered by the driveshaft. Its function is to provide you with an accurate reading of your car’s speed as you drive. It does this by turning a magnet inside the speed cup within the speedometer casing, through a process of electromagnetism. This moves the pointer on your car’s speedometer. The cable is calibrated so that the speed at which it spins corresponds to the location of the pointer. Yet like most car parts, speedo cable suffers wear and tear, and will eventually need replacing. To ensure your speedometer gives you an accurate reading for longer, we advise buying only high quality speedo cable for your car.