PS. actually not a soldier numer 103 but a slodier of the 103rd regiment.
... in most cases this means the number of an infantry regiment, but in 1914 the use of numbers on the covers were extended to all units that wore the pickelhaube, so it could be the number of a pioneer, supply or railway unit as well. Numbers were initially applied in red cloth which changed to green cloth in August 1914 and then were later applied as a stencil before all numbers were officially abolished/removed from covers by an order of October 1916.
the info ... German Pickelhaube covers with numbers on them...