Use these high-quality spark plugs to keep your boat performing at its best by preventing jittering and rough sounds. The BMR4A SPARK PLUG (86-5728) is made with a three-step trivalent plating process that uses silver chromate and zinc to ensure maximum corrosion resistance. It has a five-rib insulator design to prevent flashover. The BMR4A SPARK PLUG (86-5728) is made with corrosion-resistant plating to ensure ease of installation and removal. The triple gasket sealing process used by NGK prevents gas leakage past the shell. It has a solid copper core for better heat dissipation, conductivity, and a wider temperature range. It also features cold-rolled threads that prevent damage to the cylinder head. Key Features: It is made with a three-step trivalent plating process that uses silver chromate and zinc to ensure maximum corrosion resistance. It has a five-rib insulator design to prevent flashover. It is made with corrosion-resistant plating to ensure ease of installation and removal. It features cold-rolled threads that prevent damage to the cylinder head. Specifications: Brand: Autowares SKU: 86-5728 UPC: 087295057285 Weight: 0.15 LBS