Inert 75mm 1916 Austro-Hungarian shell casing used in the Skoda 7.5cm Gebirgskanone M.15 during WWI. This 75x129mm casing is made of brass, and markings can be seen clearly. The Skoda 7.5cm Gebirgskanone M.15 was a mountain gun used by Austria-Hungary during WWI. In German service it was known as the 7.5cm GebK 15.