Aluminium Tube (Luftwaffe) 'Z69D'

[Bever]

In attachment, several images , on the images some of the dimensions of the item.
Length is approximately 4cm (maximum)

Markings : Luftwaffe stamp , Z69D

Diameter of the smaller ring in the middle : 12,5mm
Diameter of one side : 15mm
Diameter of the opposite side : 14mm

If anyone knows what this item is or what it is used for , feel free to let me know.
Thank you

 

[MINENAZ16]

Hello,
Herewith Sir :

 

[Bever]

Thanks a lot.