In kendo equipment, the men is used to protect the head and the throat. The men, apparently, was first made by a man named Naganuma Shirozaemon Kunisato. Naganuma and his father Yamada Mitsunori were trying to develop equipment such as the men and kote so that kenshi could strike each other in practice without risk of injury. Naganuma eventually produced the men in its final form. The men consists of the mengane (metal bars), uichiwa (inner ring), mendare (head-cover/shoulder-cover) and tsukidare (throat-cover).
The mengane is the metal part that covers the front part of the men. It forms a grid in order to protect the face while giving a clear vision. The materials used recently for the mengane are duralumin and stainless steel. Iron was used for a long time, but as people have begun to pursue lighter material, it has shifted to alloys.
The uchiwa protects the outline of the face. It is where you fit the face, so one must choose the correct size and fit the face in so that it does not wobble.
The mendare hangs from the uchiwa to the shoulders. When you are striking each other in practice, sometimes miss hits will strike the mendare. It is important to have mendare that is long enough to protect the shoulders.
The tsukidare protects the throat from strikes. It is often made of cow skin.
Putting on the men can often be difficult for beginners, but it is easy once you get used to it. The men cannot protect the back of the head. When you fit the men directly on your head, it can get moldy and damaged quickly, so it is good to wrap a towel around your head first. Then you can put the men on and tighten it with the strings.