Check the listing for details. Yamaha YFZ450 YFZ 450 Spring Kit Head +1mm Ferrea Intake Exhaust 5 Valves Seals. Condition: New. Listed at 409.99 USD. Brand New Ferrea Racing Complete Rebuild KitSprings, Titanium Retainers, Seat Locators+1mm Oversized Intake & Exhaust Valves With Seals Kit Meticulously designed! Made in the U.S.A using the highest quality materials. Yamaha YFZ 450 ATV Full Fitment List: Yamaha YFZ 450 2004 - 2009 Carburetor Model Yamaha YFZ 450R 2009 - 2020 EFI ModelYamaha YFZ 450X 2008 - 2020 Yamaha YFZ 450SE 2010 - 2020Yamaha WR 450 2003 - 2015Yamaha YZ 450F 2003 - 2009 This kit Includes: Titanium Retainers (5)Single Valve Springs (5)Spring Seat Locators (5)Stainless Steel Intake Valves +1mm (Pair (2) Stainless Steel Intake Valve Center +1mm (1)Stainless Steel Exhaust Valves +1mm (Pair (2) Viton Hi Temp Valve Stem Seals (5) (May be red or blue, same viton material)Outter Intake Valve Specs:Head Diameter: 28.00 mmStem Diameter: 4.48 Inner Intake Valve Specs:Head Diameter: 28.00 mmStem Diameter: 4.48 Exhaust Valve Specs:Head Diameter: 29.00 mmStem Diameter: 4.97 Intake & Exhaust Spring Specs:Seat Press: 38lbsOpen Seat Press: 85lbsMax Lift: .430 (.433")