Swimming/Scuba Diving Fins for Shallow Area (XL) Size L: 6.5-7.5(M)/7.5-8.5(F) Size XL: 8-8.5(M)/9(F) (U.S. Size) Short, straight blade helps maintain proper kick/stroke tempo. Foot pocket offers comfort and superior flexibility. Soft silicone short blade training fins help you develop a stronger, faster flutter kick. Speed Fit clips for quick, easy adjustment.