FREE 3 BUSINESS DAY SHIPPING! These sturdy and long-lasting SCUBA fins are the preferred choice of the US military and special ops forces. The curved blade design provides better propulsion with each kick, and the open-heel style is designed to wear with dive boots. PROVEN DESIGN — Sturdy design is long lasting and extremely durable. MILITARY'S CHOICE — Preferred choice for US Military & Special Operations Forces (SEALs, Special Forces, MARSOC, Combat Controllers, PJs etc) OPTIMAL PERFORMANCE — Curved blade design for better propulsion with each kick. OPEN HEEL- Open heel style is designed to wear with dive boots.   SIZES: XXL: 46~48 (13~15) US Mens XL: 44~46 (11~13) US Mens L: 42~44 (9~11) US Mens M: 40~42 (7~9) US Mens