This appears to be a white 4 pocket HBT jacket. It looks as though there was insignia on it at one time but it has been removed. Drill uniforms were often kitted out with insignia although it was not a regulation to do so. There are faint ink stamps inside. The chest measures 37 3/4" and waist 34 1/4".
It is in decent to good overall condition with a little staining and some loose threads (where insignia was removed) but no major damage. It is missing 2 buttons, one at the collar and one on the lower left pocket. The buttons look like original officers type buttons.
In the film 08/15 part 1, this type of uniform is shown being worn by the soldiers serving beer at the officers party. It is distinctly this uniform and not the standard 2 pocket drill uniform they normally wear throughout part 1 of the film. Given that the film was produced so soon after the war and many of the stars were actual German veterans it is possible this gives insight into exactly what this uniform was for. Here is a scene of the film, you can see the tunic about 3 minutes in.
This item ships for free in the US!