Mares Avanti X3 Open Heel Fins Size Chart
  XS SM REG XL
US Men's shoe size 4-6 6-9 9-11 11-13
US Women's shoe size 5-7 7-10 10-12 12-14
European Men's shoe size 35-38 38-43 43-45 45-48
Length (inches) 22.25 23.75 25.5 26.5
Width (inches) 7.25 7.75 8 8.5
Weight (pounds per pair) 3 3.5 4 4.5

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