Granite Gear Air Pair Size Chart
  Small Medium Large X-Large
Dimensions (in) 4.5x2.7x11" 5.7x3.1x12.6" 6.5x3.5x14.2" 7.2x3.9x15.7"
Capacity (cubic in) 125 200 250 370
Product Weight (grams) 14 16 19 21

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