Like the tail fin of a humpback whale, SCUBAPRO's Twin Jet Fins use a split-hydrofoil shape to deliver more forward motion with less effort. Result: more power with less effort and drag. All SCUBAPRO split fins employ a truly remarkable propulsion technology that uses an unconventional hydrofoil shape to produce forward motion with considerably less effort than any other conventional blade. This secret lies in the patented design, which allows water to flow between and around each of the twin blades, which flex independently to produce propulsion in much the same manner as a propeller. Blades are also angled to provide symmetrical power on both up and down strokes to achieve seamless propulsion. Technical Information Patented split-fi n propeller technology - proven to deliver more forward motion with considerably less effort than traditional blades. Drag-reducing vents substantially decrease resistance on both up and down strokes. Extended soleplate acts like a lever to enhance power stroke. Extra-wide foot pocket is ideal for wearing with a dry or semi-dry suit - also very comfortable to wear with standard warm-water boots. Quick-connect swivel buckles. Spring-Heel Straps also available separately. Moulded from a stiff compound to deliver a slightly negative buoyancy.