do you know what the difference in dimensions...
do you know what the difference in dimensions are from the small to the medium?
According to Timbuk2's website this pack only comes in a Medium size. Here are the interior dimensions (so your laptop must be smaller than these measurements).
Width: 18.3 inches
Height: 11.6 inches
Depth: 6 inches
See this webpage for reference: http://www.timbuk2.com/tb2/products/wingman-duffel-bag