This is an entirely sealed plain box, save for a lock and a sign which reads "DO NOT INSERT AND TURN KEY." When you insert the key, it starts to ring and does not stop (unless - of course - you know the trick). Shown here is a trial run of the box peeking the curiosity of a coworker. I mailed it to my friend in Canada shortly thereafter. To learn more, please visit: http://www.instructables.com/id/Prank-Box/
