Introducing a more robust valve than the stock KTM valves. These match the exact dimension of the stock 390 valve and are drop in replacements. The stock KTM exhaust valves are friction welded in the middle to make it easier to produce cheaply; and are made of standard steel. These valves are made in Germany with extreme precision for maximum horsepower and durability. This does come at a cost as they are a total of 6.2 grams heavier than the stock 390 valvetrain, but if running our titanium retainers the additional base pressure on the spring accounts for this weight gain. If you have any questions on application just email us and I will be happy to answer you right away!