Experience optimum speed without fatigue with U.S. Divers Hingelflex II Snorkeling Fins. Hingeflex II fins incorporate Pivot Flex technology with a detached foot pocket and webbed split-fin designed to deliver power while reducing foot and ankle fatigue. With a compact design, Hingeflex II provide great travel fins that comfortably fit in your vacation luggage. Manufacturer model #: FA2634001. Pivot Flex fins: less fatigue, more energy; Soft, comfortable foot pocket with dual-composite heel straps; Easy-adjust buckles; Dual-composite blades channel water more efficiently;