This is a militärpaß for a Bavarian soldier from a Luftschiffer Ersatz Abteilung. The man’s name was Fischer. He was born in 1898. He joined the army in 1917 and was initially assigned to a Bavarian Luftschiffer Ersatz Abteilung. The militärpaß has a flip down page where you can see his complete service for nearly two years of WW I. In addition to numerous unit stamps from his initial unit, a stamp for his assignment to Feldluftschiffer-Abteilung Nr 1 is also present. A unit stamp for a Prussian Luftschiffer-Abteilung also appears, which I find particularly interesting. The militärpaß comes in a protective jacket. It has a wealth of material to research and dig into.