The coffee mug is a dinnerware item used for carrying and containing coffee and tea. It is a white ceramic cup with a looped handle. The Pip-Boy 3000A categorizes this item as miscellaneous junk.
This item may be used as ammunition for the Rock-It Launcher. They are one of the most common items in the Capital Wasteland. With the release of Honest Hearts, coffee mugs are also a byproduct of crafting black coffee.