ID German Pilot button (?) WW1

[flavital]

Hi!

I am looking for information about this button, that I bought many years ago in Italy. It is made by copper and it is pretty large (diameter=28mm). On the front there is a ww1-style airplane and the back reports three small stars and "GESCHUTZT GESETZLICH". Unfortunately it only means "patent registered" or "protected by law", so no useful info apart that is probably German or Austroungaric. The plane image on the frontside closely resembles the WW1 German flieger badge, so I suspect it could be related to a pilot uniform.

Please help me to catalogue this puzzling piece! It's like 25 years I'm trying to...

Thanks in advance :D