US Box Fin X1 V4 21cm Select SM040150021

US Box Fin X1 V4 21cm Select SM040150021

Description:

The Select X1.V4 21cm is a versatile US Box surf/wave fin engineered to work across multiple board setups, including Quad, Thruster, Twinzer and Single configurations. Its 21 cm blade provides a balanced mix of drive and maneuverability, making it suitable for a wide range of wave conditions and rider styles. The fin is built from a durable composite construction that delivers responsive flex and long-lasting performance in repeated wave impact and saltwater exposure. Select’s X1.V4 sizing grid and box options allow riders to tailor fin placement and pairing to match their preferred feel—more hold or more release—without needing multiple fin families. The shape and foil emphasize efficient water flow for improved acceleration and reduced drag through turns. Easy to install in standard US Box mounts, the X1.V4 is a practical, high-performance option for surfers and wave riders who want a single fin that adapts to many setups.

Key Features:

• US Box compatible: fits standard US Box fin systems for easy installation and secure hold
• Multi-setup adaptability: designed to perform in Quad, Thruster, Twinzer and Single configurations
• 21 cm blade: balanced height for a blend of drive, responsiveness and maneuverability
• Durable composite construction for reliable performance and resistance to saltwater wear
• Foil and template tuned for efficient water flow and reduced drag during turns and accelerations
• Consistent, predictable flex characteristics for improved control and feedback
• Lightweight design to minimize swing weight and improve board handling
• Simple pairing with other Select fins and box configurations to fine-tune ride characteristics

Specifications:

Manufacturer: Select
SKU: SM040150021
Material: Not specified by manufacturer (durable composite construction)
Size/Dimensions: Blade height 21 cm
Weight: Not specified by manufacturer
Color: Not specified (refer to product images)
Size: 21cm
Category: Fins
Age Group: Adults
Gender: Unisex

Recommended Use:

Ideal for surfers from intermediate to advanced levels who want a single fin solution that adapts across board setups and wave conditions. Best suited for wave and shortboard applications—use in quads, thrusters, twinzer or single fin configurations depending on desired hold and release. Performs well in a range of conditions from small, punchy beach breaks to larger, more powerful waves when paired correctly with complementary fins and board setup. Pair with compatible US Box hardware and other Select fins to dial in traction, release and directionality for your specific board and local surf.