The heart of the Express ADJ is a highly elastic armadillo" hinge at the base of the blade. Like the Power Bands of the Slingshot, it absorbs energy during the power stroke and releases at the end of the kick cycle to maximize thrust. These open-heel fins are an excellent choice for cold and temperate water divers who need a powerful, compact blade. The Express ADJ now comes standard with the Aqua Lung Spring Straps for easy don and doffing. Armadillo membrane at the base of the blade absorbs energy during the down stroke, and releases prior to the upstroke for a power boost on every kick. Rubber side ribs channel water down the length of the fin, minimizing wasted energy from the spill-over effect. A Mid-Foot Flex Joint is used to attach the blade to the side of the foot pocket. This maximizes energy transfer and reduces strain on the ankles and toes. ESBS (Ergonomic Strap and Buckle System) uses a press-to-release button that is easily operated, even while wearing thick gloves. Rubber heel straps are made with anti-aging compounds and have large finger loops at each end and in the middle for easy donning, even when wearing heavy gloves. Streamlined foot pocket provides an ergonomic fit for excellent energy transfer and accommodates a wide range of dive boots. Anti-slip rubber pads on the bottom of the foot pocket give traction for moving around on boat decks. Fins are available in multiple sizes and colors.