Device used to notify others that they are in the presence of a dickhead. The point may be reinforced by the wearer displaying said item at alternative angles, particularly back-to-front especially when facing the sun.

Device which, when fitted to the head of anyone driving a car, immediately removes any concern they may have previously exhibited for their own, their passengers, and, well, anyone elses safety.

Especially effective when driving 'modded cars'. See kev.