04-18 KAWASAKI KX250F: Kibblewhite Intake Valve Seals (Quantity 1) All valve seals are made of 100% solid Viton for long life Meet or exceed OEM specifications When using Kibblewhite spring kits, Kibblewhite valve seals must be used because of spring clearances Sold individually; unless noted Stem Dia. 4.0mm - Guide Dia. 0.285in. - Overall Length 0.310in. - Seal O.D. 0.375in.