Watch out for the cheap Chinese junk engine parts flooding the market! I make these buckets and can answer your questions. Try that with the "other guy" selling cheap Chinese junk. This is a set of (2) new valve tappets, buckets, cam followers for 2004-2016 KX250F. Race proven heat treated and phosphated chromoly steel, precision ground.  Brand New never installed! FREE SHIPPING. PLEASE EMAIL ME WITH QUESTIONS! Yes I offer a warranty on these.  Try that with the other guys.