The product is a set of nitrided valves for Harley Evo Twin Cam motorcycles, specifically designed for intake and exhaust purposes. These valves are black nitride coated for durability and are replacements for OEM HD parts 18074-83A and 18082-83. They are not a custom bundle and come with no warranty. The product is not a modification of any kind, making it a reliable choice for those looking to replace worn-out or damaged valves in their motorcycle engine.