Aeris Velocity Duo Split Fins Description High performance "split fin" technology. The Velocity duo's high performance is achieved by combining patented Nature's Wing technology with state-of-the-art materials. The Velocity duo is designed to provide greater thrust while reducing muscle fatigue. The dual blade design allows the diver to make a much more efficient flutter kick, thus reducing the amount of effort needed to propel the diver through the water. Patented Nature's Wing propeller fin technology Advanced composite materials for ideal flex and memory Rigid side rails for increased lift and efficiency Ergonomically designed foot pocket accommodates virtually all foot sizes and boot styles Angled blade for preferred angle of attack Easy adjust quick-release buckles