KPMI? solid Viton? valve stem seals are designed to have optimum fitment, allow for maximum lift, and to give maximum life. KPMI? Red valve stem seals are resistant to high temperatures, petroleum products and the corrosive gasses that are the by-products of combustion. These seals retain their ability to seal in situations where other materials could harden and allow oil to enter the combustion chamber causing detonation, carbon build up and a loss of power. The Red Ones are truly the racer*s choice.