Semi-rigid battens set in the soft elastomeric blade controls the precise wing shape to optimize thrust and reduce drag; The split blade deflects with the slightest kick to form a pair of wings that slice through the water with reduced drag, propelling you forward; Large surface area blade improves pivoting, turning and alternate kicking styles; Thin, yet strong and highly flexible hinge points between the semi-rigid battens cause the blade to react quickly and efficiently to the slightest kick; Internal sole plate creates rigid platform beneath the foot for greater power transfer to the blade yet allows for a soft, comfortable foot pocket; An Atomic exclusive, patented buckle system design features easy, one-handed quick release of the buckle from the fin; Unique rust-resistant Stainless Steel springs are designed with variable pitch geometry for easy stretching, yet resistant to deformation if overstretched