Seattle Sports H2Zero Omni Dry Stuff Sack Size Chart
  Small Medium Large X-Large
Dimensions (in) 7.5x15" 9.5x18" 11.5x24" 12.5x28"
Capacity (cubic in) 600 1275 2500 3500
Product Weight (lbs) 8 oz 13 oz 1 lb, 2 oz 1 lb, 6 oz

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