At least this is how JL Larcade qualified these Tschapkas from the first months of 1915, before the ordinance of April (soon 100 years ago) which imposed the grey metal fittings. This one for 3GUR.
Bruno
Thanks to all of you for your nice comments. This one has characteristics of a privately purchased helmet. Joe, isn't it you who posted pictures of a period catalogue advertising M15 Tschapkas with detachable mortarboards?..
Bruno