Badge "Mit vereiten kraften"

[strelets]

Hallo,

does anybody know to what event is this badge devoted to.
On reverse is engraving 1914-15 M.V. and rot cross.
On Franz Joseph’s shoulder there are marks – the first (3 (dog’s head) А) and the second TS, what do they signify?

[Don D.]

With united power? A pin commemorating their united war effort.

[saschaw]

A pin commemorating their united war effort.

Correct. And this one is of Austrian original, with the Austrian Emperor and crown in front, plus typical Austrian hallmarks. Very similar stuff was made in germany too, but then with Wilhelm II. in front of the Austrian Emperor.
The double "A" shows that all parts are made of the same metal - here silver, as the dogheads indicate.

[strelets]

thank you!!!
Is it rare badge or ordinary one? How much should it be?