This ring is very special! Ring was found in POW camp near Ejpovice (Pilsen). In the movie you can see Kneissl on the way to that POW camp. See video here: Michael Kneissl
SS-Obersturmbannführer Michael Kneissl was a leader of SS Wachbataillon Prague
*30.11.1891
+ 29.3.1947
SS no. 24990
Diameter: 21,7 mm
The ring is published in the book "SS-Totenkopfring - Himmleruv prsten cti":