Honda XR400R TRX400EX Sportrax TRX400X Wiseco Piston Kit – 88.00 mm Bore Wiseco 4 Stroke Forged Series Piston Kit, 88.00 mm Bore, 10:1 CR The Wiseco team has remained at the forefront of powersports performance through every era and evolution, including the development of high-performance 4-strokes. Today, Wiseco’s forged 4-stroke pistons are designed for each specific engine application and built to the tightest tolerances for the ultimate combination of performance and strength. Proven at every level of riding, Wiseco 4-stroke pistons are ready to deliver the power and reliability you’re looking for. Engineered, forged, and machined in the USA in Mentor, OH Designed and built for each specific 4-stroke powersports engine Improved tensile strength of forged material optimizes strength and service life Dedicated forgings allow for optimized strength-to-weight ratio Includes high-quality piston rings, wrist pin(s), and circlips