ScubaPro Seawing Gorilla Open Heel Fins Size Chart
  Small Medium Large X-Large
US Men's Shoe Size 4-5 5.5-7.5 8-9.5 10-13
US Women's Shoe Size 4.5-7.5 8-10 9-11 10-12
UK 3.5-4.5 5-7 7.5-9 9.5-12
Euro 34-37.5 38-41 41.5-43.5 44-47
Product Weight (lbs per pair) 3.75 4.2 4.7 5.35

These are general guidelines only, sizes are not guaranteed. But no worries, since at LeisurePro we offer our exclusive PFF Guaranty