Dynatek Twin Coils Four Output Towers Single-Fire Dynatek Twin Coils Four Output Towers has a design that incorporates two individual performance ignition coils into a single, with an easy-to-mount package that is only slightly larger than the stock coil and uses the stock mounting bracket. Features: The standard for performance and ease of installation for single-fire applications Delivers spark voltage in excess of 30,000 volts with fast rise times and high energy For use with any electronic advance ignition system that incorporates dwell control Coils are rated at 3 ohms Made in USA Note: Not for Twin Cam applications.