Blind Primer C12

[blackwatch]

I,m looking for info about this primer or plug.
This one was found in the Netherlands nearby a coastal bunker.

 

[greif]

It is a Dutch primer plug and is made of zinc. Used by the Dutch coastal guns.
Designation: "Ontstekingsdop No. 1 os. (massief)"
It has the same thread as the C/12 primer.

 

[blackwatch]

Many thanks greif.