What is this button?

[Theodor]

Hi,
Can you please tell me what this button is? 15 - is that 15th Regiment or something like this? Also, is it Wehrmacht or something else /SS... SA... HJ/, it is marked on the back with RZM and M5/75. The volor is much lighter gray, the picture became dark.

[reidmuller]

i think it is the company so 15th company
so for example 15th company ot the 916th GR of the 352nd VGD
and it is army but may be SS and LW too?

[Dave Suter]

Heer only. Indicates the company.

[Theodor]

Thank you very much!