Function of product: High performance spring can increase speed and reduce clutch failure. 2000RPM springs provide strong engagement and higher RPM at take-off, sacrificing some smoothness for increased power during acceleration. Fits: 50cc-100cc GY6 engines, as well as 139QMB and 1P39QMB engine models. Compatible with Scooter, Moped, ATV. Production materials: Made from high strength materials for stable performance. Surface coating resists wear and provides a glossy appearance to enhance your motorcycle's look. Please Note: Verify compatibility with your motorcycle before purchase. Understand the differences in spring performance based on RPM range. Performance of upgraded parts may vary due to multiple factors. Scooter 2000RPM clutch spring torsion spring compatible with Aerox, Axis, Breeze, Jog, Neo 50cc AC models. 2000RPM clutch spring - torsion spring Note: Red spring rated for 2000RPM (2K) Color: Red Material: Metal Package Contents: 3 x Clutch spring (Small) 1 x Clutch spring (Big) Only the above items included; others not included. Note: Lighting effects and display settings may cause slight color variations between the image and actual item. Measurement may vary by +/- 1-3cm.