Non aviation (Wehrmacht field kit item) Identity

Ok, It’s not aviation related I know, but anyone on here identify wehrmacht equipment?.
This is a bakelite bottle found near Luneburg in 1989. It has a serial nunmber of:
Art.nr.0.38E5108 with a circle containing the letters ‘gfj’ preceeding the number. Another circle ends the serial with the year ‘1942’ within. The top still unscrews and the smell from inside seems…well..medical 🙂
This seems to be the forum for identifying all manner of parts and pieces, so over to you!