RLP Spark Plug Wire Set - 8.0mm - Universal Fit - Carbon Graphite Core, Red Silicone Jacket, 90 Degree Boots - For Vehicles with Internal Combustion Engines

Insulation is not very good. Have wrapped headers and still had missing issues after engine is warmed up. Temp at plug boots was about 280f.

Decent quality for the price

There is maybe a 22ga wire inside this. About the thickness of wire I would expect to see 4 of inside a USB cable. Not the size I would want to rely on delivering spark to an engine.