Uboat tauchretter mouthpiece

[Bonecollector]

Hi

Can anyone tell me whether this tauchretter mouthpiece was made by Drager or Auer, or were there other contractors making these parts? Can someone tell me whether it's early or late war. The top section is steel or an alloy of some sort (it is slightly magnetic). The bottom part is plated brass. Unfortunately it's missing the valve and rubber mouthpiece. Many thanks