Tusa Imprex Duo FinsDescription Features The Imprex Duo fin features TUSAs patented Angled Blade Design and multi compound foot pocket, increasing power transfer to the fin blade. The Imprex Duo also features a two material design for high performance and reinforced side rails creating stability, for powerful propulsion without fatigue. Two material design for high performance 20 degree Angled Blade Design Multi compound foot pocket increases power transfer to the fin