Sierra distributor for Ford engine. Cobalt magnets and half-effect trigger for stable timing and precise spark distribution. Compensates for inherent electronic delay. Synchronized peak current and spark timing reduce heat buildup. Integrated Ignitor II technology with adaptive dwell control. Non-ventilated cap equipped with stainless steel fasteners. Triple screen arrestor for added protection. For Ford 351W (conventional rotation) applications. Sierra Part #18-5481.