Kooks products are 100 Percent Manufactured in the USA and are made with the highest quality materials. Kooks Headers and Exhaust make the most power in the industry, specifically designed for best fitment, performance, and optimal sound. Kooks products are made of 304 Grade Stainless Steel and come with a limited lifetime warranty. Every Kooks product is dyno tested and race proven. Kooks is 3 generations of being family owned and operated.