What is a "have a nice day" middle finger mug?

The "have a nice day" finger mug is a sarcastic mug suitable for hot or cold beverages that allows the user to surreptitiously give viewers the finger. The mugs are available in a variety of colors and designs, but they all feature the up thrust middle finger motif.

The most common design of the "have a nice day" mug has the printed motto placed on the outside of the mug within easy view, using an easy to read from a distance font. The gesture of the up-thrust middle finger extending from a clinched fist is usually placed on the bottom of the mug in such a way that when the mug is held with the motto pointed at someone and tilted so the bottom is visible, the middle finger points at the person as well.