Mares Volo Power Open Heel Fins - Lightweight Scuba Diving Fins for Snorkeling & Swimming | Perfect for Ocean Adventures & Pool Training

OPB - Optimized Pivoting Blade
Allows the blade to maintain an optimal angle throughout the kicking cycle, whereas traditional fins achieve this only during a small portion of the cycle. OPB produces a constant thrust, which minimizes fatigue and produces fluid movement through the water.

Channel Thrust
Soft longitudinal inserts allow a controlled deformation of the fin blade while kicking. This channel shape moves a greater amount of water resulting in more thrust for the same effort.