- Precision Fit : Designed specifically for 50CC 139QMB engines, this 39mm piston ring set guarantees an exact fit, enhancing engine performance and longevity. - Enhanced Performance : Experience improved compression and sealing with these piston rings, which lead to better performance and increased fuel efficiency. Ideal for beach scooters, scooters, and dirt bikes, these rings will maximize your vehicle's potential. - Durable Construction : Crafted from high-quality materials, these piston rings resist high temperatures and pressures, ensuring reliability even in extreme operating conditions. - Easy Installation : The set includes all necessary components for straightforward installation, making it accessible for both professional mechanics and DIY enthusiasts. - Application Scenarios : Perfect for upgrading your beach scooter for enhanced acceleration on sandy terrains, improving your scooter’s efficiency for daily commuting, or optimizing your dirt bike’s power on rugged trails.