The TWIN JET MAX features a dual-compound design that offers a slightly stiffer blade with a little more feedback than what you might expect in a flexier fin. Employing what's known as "propeller technology," the distinctive split hydrofoil shape of the TWIN JET MAX blade 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. These blades are also angled to provide symmetrical power on both up and down strokes, creating a smooth and stable kicking motion that gets you moving without wearing you out.