Flare gun

[RDUNE]

I found this in a drawer of my grandfathers workbench earlier tonight. Some internet searching has revealed that this is a pre-war German Flare gun, or as one website called it "a tank pisser-offer". I just wanted to see if anyone had any more information they could share about it.

I apologize for the poor quality of the pictures.
The dollar bill is just for size reference.

The little inscription reads: "Waffenfabrik Walther Zella Mehlis (Thur.)" with two little dots over the U in 'Thur'.

The serial # is 19166.

I dont know much about this particular guns history, my grandfather said he remembers mailing it home, but doesnt remember exactly how he acquired it.

[Pierre N]

early Walther model 34 , here a video , flare gun in action :
YouTube - Den G - german flare / signal gun WWII WW2 WK2

and the best link of flare gun :
Modele 34