Description Norton® 750 1968-1973 Norton® 850 1973-1977 Triumph® 500 & 650’s 1951-1962 Triumph® 650 / 750 1963-1983 Triumph® TRIDENT ™ 1971-1976 KPMI® Red 100% Viton valve stem seals are designed to have optimum fitment, allow , 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 racers choice.A0.500”±0.010”B0.445″C0.230″D0.280″MaterialRed Viton®NoteUse the diagram and specifications to ensure your valve guide shares the same dimensions for a proper fitOverall Length0.465″QuantityPkg. of 4 (Seal Style 1)ReferenceSee Figure 1Seal O.D.0.550″Stem Diameter5/16″