Wiktionary
open box
a. Pertaining to a product sold by merchants at a discount, because the item was returned but found not to be defective.
Usage examples of "open box".
Leila swung around, which sent macaroni flying out of the open box.
In the process of time it comes about that without any other stimulus than that of the box which originally called out the bodily habits, he begins to say 'box' when he sees it, 'open box' when he opens it, etc.
The fire-breathing hologram danced above the open box as Cally gasped at the contents.