The official term for the "German Helmet" or "Nazi Helmet". Stahl is the German word for steel, helm meaning helmet. It's design was based on the medival Sallet helmet. Since WWI, it's had a few different versions:
M16-Came about in 1916
M18-1918
M35-1935
M40-1940
and the M42-1942
Its a german helmet used in world war two. Not much else to say. (You looking this up for school or something?) one important thing is. THIS HELMET CANT STOP BULLETS ONLY SHRAPNEL.