Dyna Leads are made from high grade automotive, silicon jacketed, high tension cable. All wires are supplied with finished spark plug boot ends and loose coil terminals to allow the final length to be determined by the user. Wires are available with a solid copper core for use on older vehicles where electrical interference is not an issue. For use on new vehicles with electronic advance ignitions or other sensitive electronic equipment, use DYNA suppression wires with a high grade graphite core for best performance and electrical noise suppression. Both wire types ensure maximum energy transfer.