Wiseco VIS003 Premium Stainless Steel Intake Valve Fits: Honda XR400 1996-2004, TRX400EX 1999-2008, TRX400X 2009-2013 Wiseco's stainless steel valves are made from premium materials and manufactured to the highest quality specifications A one-piece, forged construction offers high strength and fatigue properties Chromium nitride coating offering surface hardness and wear resistance Each design is a drop-in application and requires no piston or head modifications and will work with stock springs and valve-train