Replica German Stahlhelm Helmet by COMMANDO

A replica of German style helmet or Stahlhelm (German for "Steel helmet")

The Stahlhelm German military helmet was introduced into regular service during the Verdun campaign in early 1916 in response to the significant increase in head injuries suffered by troops due to the much more lethal artillery and grenades employed during the trench warfare that developed.  

The Stahlhelm is broadly based on the 15th-century sallet helmet, which provided good protection for the head and neck and was considered by many to provide the best protection of the helmets during WW1. However, the large, flared skirt tended to make it difficult for soldiers to hear, distorting surrounding sounds and creating an echo when the wearer spoke and the ventilator horns often let cold air in during the winter, requiring the wearer to block the vents with mud or fabric. 

The German Stahlhelm, with its distinctive "coal scuttle" shape, was instantly recognizable and became a common element of propaganda on both sides, just like the Pickelhaube before it.