@mike8 thanks for reaching out with this question! To make sure we're clear, it sounds like you're looking for a duffel-style bag with an external pocket that is specifically designed to hold a coffee mug (presumably that is full of liquid and therefore needs to stay upright!) - assuming that's true, here are a few tidbits:

• The majority of the duffel bags we carry are pretty streamlined on the outside of the bags, mainly to eliminate the risk of external pockets getting caught up/damaged during travel (think: baggage claim conveyor belts); in addition, because many duffels can double as backpacks, the rotation of the bag then eliminates the effectiveness of a pocket designed primarily to carry a mug in one direction

With that said, we found a few duffels you might consider, noting that they aren't designed specifically for carrying a coffee cup:

• Kuhl Konvoy 45L - has an external snap pocket
• Patagonia Black Hole Duffel, REI Co-op Roadtripper Duffel, and United By Blue 55L - all have an external zippered pocket where you might be able to slide a coffee mug for transport to your truck

While we recognize these aren't exactly what you are looking for, we hope this helps gives you some ideas - in addition, please let us know if it would be helpful for us to suggest a few pack styles that may feel like a duffel and specifically offer the coffee mug pocket!

Thanks, @REI-JenK  JenK.  I think that will do it.  I will go to Denver's REI store right now to look up those duffels & use my coupon.  Thanks for explaining why I could not find one with an exterior pocket (conveyor belts, inspections) that I could, perhaps, use for a coffee cup.  I could not figure that out because the guys with whom I work have small duffels in which they carry their possibles, and they all have an exterior pocket which they use to carry their coffee.