Longer blades store more energy and produce better spring action, resulting in ease of kicking with less noise while hunting underwater. Our new long blade plastic fins come with The VELOC, Riffe's new streamlined fit, flexible Thermoplastic Rubber foot pocket. 20 degree angle. Lightweight and comfortable. Perfect for entry level and intermediate spearos. Size Chart 36/37 | 2-338/39 | 4-540/41 | 6-742/43 | 8-944/45 | 10-1146/47 | 12-13