This is a new set of 4 current production Viton valve stem seals for the Evolution '84-'99, Evo Sportster 883 '86-'03, XL 1100 '86-'87, Evo Sportster 1200 '88-'03, Twin Cam 88 '99-'04. These are not factory seals that have been sitting around hardening for 30 years. These are made now.....in the 21st century! Superior metal clad Viton construction containing 5% Teflon for reduced friction and wear. Viton has a much higher resistance to temperature and chemicals and will maintain their elasticity for many years. These are the best on the planet, satisfaction guaranteed or your money back. Please contact me if you have any questions. Thanks for looking!