Quicksilver 815407Q5 Distributor Cap Kit - Marinized V-6 Engines by General Motors with Thunderbolt IV and V HEI Ignition Systems Cap is made from a blend of PBT and pet plastics for increased strength, stiffness and resistance to warpage Produced to Meet Mercury marine original equipment Manufacturer specifications to best protect your mercuries engine Solid brass inserts resist corrosion and electrical pitting for long service life High strength to weight ratio rotor is designed for durability and resistance to thermal cracking Designed to resist rift interference with onboard electronics