The origin of these bricks is still unknown. As far as I know all known bricks come from the same German collector.
Logo: modern logo
Inner wall: thick
Inner ribs: None
Flowrib / center line inside top surface: No.
Mold pip: on the stud.
Mold number: None.
Mold position numbers: None.
Intellectual property protection: None.
Design ID (3001): No.
- Grooves/ridges on the inside top surface.
- No mold markings
Colors known: Transparent light blue, transparent neon-green.
- Where were these bricks made, and what were they used for?
- Why were these ridges made?
- Can we find more colors?
The brick does not work as a reflector.
Very recognisable ridges inside the top surface. No other markings inside the brick.
Showing the profile of the corrugated grooves/ridges inside the brick.