This project was the result of the exceptional experience of Martin Stepanek, one of the greatest competitive freedivers of all times, combined with the 30 years of experience of the C4 carbon fiber fin Co. of Marco Bonfanti. Stepanek's signature fin features TR50-Hypertech Big Square, an even more responsive carbon fiber material compared to the already highly proven T700 adopted previously by C4. After a year of long testing, Martin carefully developed a fin with C4 that fit his needs and catered to the most important needs of freedivers and spearfishers from his experience in American waters.

• Developed by Experience of Martin Stepanek and 30 Years Experience of C4 Carbon Fiber Fin Co.
• Blade: TR50-Hypertech Big Square: Responsive Carbon Fiber
• Medium, ideal for Divers Weighing between 175 lbs. and 200 lbs.
• Non-Vented Long Fin Design
• Blade Angle: 22° Degrees

Developed by Experience of Martin Stepanek and 30 Years Experience of C4 Carbon Fiber Fin Co.C4