2x Exhaust Valve Kit for Yamaha 28P-12121-00-00 5VK-12113-00-00 5H0-12119-00-00Fits Following Yamaha Models: Grizzly 550 YFM550 4×4 2009 Order Includes: 2 x Exhaust Valve: 28P-12121-00-00 Exhaust Valve Length: 1.10″ | 28.0 mm Exhaust Valve Diameter: 3.77″ | 96.0 mm 2 x Inner Valve Spring: 5VK-12113-00-00 Width: 0.98″ | 25.0 mm Height: 1.61″ | 41.1 mm Thickness: 0.14″ | 3.6 mm 2 x Valve Stem Seal: 5H0-12119-00-00 Length: 0.47″ | 12.0 mm Width: 0.35″ | 9.0 mm Inner Diameter: 0.18″ | 4.7 mm Outer Diameter: 0.37″ | 9.4 mm 4 x Valve Cotter: 4G0-12118-00-00 Width: 0.14 ” | 3.8 mm Length: 0.33 ” | 8.5 mm Height: 0.23 ” | 6.0 mm **