So fast and responsive they're scary. Precision blend of hydrodynamics and materials technology for ultimate comfort, efficiency and performance. The Viper full foot blade's Flexible Power Thrust Channel directs water off the tip of the blade for improved power and efficiency. The engineered channels and side rails direct water flow off the tips of the fin without allowing water to "spill" from the sides of the blade for uncompromising power and efficiency. The New Patriotic Themed Product Line Demonstrates Commitment to Supporting Veteran's Programs Across our Country.