Flexible, responsive fin for air SUPs and longboards: Soft center fin made of PVC delivers predictable flex and quick recovery, improving control in river running, smallwave surfing, and cruising. The flexible design absorbs impacts and returns to shape for reliable handling. Fits standard longboard fin boxes: Designed to work with general longboard/longboardstyle fin box systems. The included screw secures the fin firmly to the board to prevent unintended detachment during use. Improved tracking and maneuverability: Hydrodynamic profile promotes stable straightline tracking while still allowing smooth turns and quick responses when you need them. Balanced areatoweight design provides control without excessive drag. Practical size and durable material: Measures 18.7 x 14.2 cm. Constructed with PVC for durability in freshwater and surf conditions while remaining lightweight for easy handling and installation. Color options and compatibility: Available in black, yellow, and green to match or your board. Actual color may vary slightly due to brightness and viewing conditions. What's included: 1 surf fin and 1 screw for easy installation into standard longboard fin boxes. Use scenarios: River running and mild whitewater: Flexible PVC center reduces catch and helps maintain control through currents and small drops. Smallwave or beach breaks: Provides responsive turning for riders who want a balance of stability and maneuverability. Inflatable SUP cruising and longboard commuting: Fits common longboard fin boxes for recreational rides and intermediate training sessions. Suitable for recreational and intermediate riders seeking a reliable, easytoinstall fin that balances flexibility, tracking, and durability.