Feature: 1. PART NUMBER: The piston set has the part number 6H4 11631 01 for reference, making it an exact OEM replacement for your outboard motor. 2. STRONG COMPATIBILITY: This piston kit is a direct replacement for outboard motor 40‑50hp 3 cylinder engine, ensuring a perfect fit and optimal performance for your boat. 3. ENHANCED ENGINE EFFICIENCY: With a piston diameter of 67mm, this kit helps improve engine efficiency by providing the right compression ratio. 4. EASY INSTALLATION: Designed for direct replacement, making the piston easy to install without any modification. It saves you time and effort, allowing you to enjoy your boating adventures. 5. HIGH PERFORMANCE: The pistons help ensure smooth engine operation and maximize power output for a better boating experience, providing more powerful mechanical energy. Specification: Item Type: Piston Kit Replacement Part Number: 6H4 11631 01 Piston Diameter: Approx. 67mm/2.63in Installation Type: Direct Replacement Applicable Models: Fit for Outboard Motor 40-50hp 3 Cylinder Engine. Package List: 1 x Piston Kit (6PCS) Note: 1. Before purchasing, please verify the part number and model to ensure compatibility. 2. If you are not a professional, it is recommended to seek the assistance of a professional mechanic to ensure the best shopping experience.