Filson's Medium Field Bag is big and tough enough to hold your binoculars, field guide, and lunch when you're getting all naturalisty out in the woods, but it's also more than stylish enough to be used as a briefcase or travel satchel. The twill fabric will stand up to prickers, light rain, and heavy commuting, and the bridle leather shoulder strap and details provide killer class that'll look better on your 100th birding mission than it does on your first.