A ninja accessory commonly seen in the manga/anime "Naruto."
They are bands of metal with a symbol in the middle used to represent the nin's home village and three bolts on either side.
Generally they are connected to a strip of cloth of a dark color such as black, grey, navy, forest green, brown, and maroon.
Other variations are connected to cloth so that they may be worn as bandanas, hats, or underwear shaped things on your head.
They are meant to be worn at the forehead, but also appear across the eye, over the eyes, on the head backwards or at an odd angle, as a necklace, as an armband, around the waist, around a thigh, or connected to something the nin carries around with him.
"My forehead protector has a leaf symbol on it because I come from the village Konohakagure."