I suspect that you've seen this one already Joe, I know that I've posted it somewhere but can't remember where
I believe this is for the Nationalsozialistische Opfer-Gruppe in Siemensstadt.
Siemensstadt is on the outskirts or Berlin. An area of residential properties built by Siemens for their workers, much like Bournville in the UK was built by the chocolate company Cadbury's.
Interesting note is that it was made by M.Sedlatzek CHLBG, a jeweller in Charlottenburg which is just down the road to Siemensstadt.