Auction is for one set of 4 viton valve seals for a Kawasaki Mojave 250 1987-2004, these are designed to have optimum fitment and give maximum life. They are resistant to high temperatures, petroleum products and corrosive acicdic gasses that are by product from combustion proceess.These seal retain there ability to seal in situations where others harden and let oil enter the combustion chamber causing carbon build up, detonation, and loss of power. Best you can buy at the best prices. Same seals we use on our high performance race heads. Will work with aftermarket guides also. Thanks for looking