Hyper Ground cables provides direct ground path from battery negative to body, chassis, and engine components for better electrical circulation. The cables also have about 10 times less impedance than factory ground systems to prevent current loss. Hyper Ground uses thick gauge 99.99% pure copper, and connects directly from the cylinder head and other points under the hood to the battery, to provide an ultra low resistance connection. * Many color cables are available from Hyperground, but we only carry the best GOLD and SILVER ground cables for BEST conductivity. We also use this same ground cable on our race car! * Please choose the color and size when ordering. With battery still in factory location: Small - normal 4 Cylinder / Medium - Mid/Large sized 6 or 8 cylinders / Large - All Euro BMW with rear trunk mounted battery.