This droid caller was made from an old Kobold camera flash. There were many flash variations made by Kobold which were used for all the droid callers. The one used for Luke's droid caller from A New Hope has a stepped transition on the top section and a smooth bottom with a smooth edge.
Kobold Flash Attachment
From the collection of Jim Fowler
This is the variation used for this prop.
The middle section of the flash is either the original black textured finish or it was painted by the prop department. Some A New Hope photos seem to indicate that a silver Kobold logo is intact on the flash suggesting black was the original color though we have yet to see a Kobold like the one pictured above with a black bottom.
An approximately 1 inch D-ring was attached through a hole drilled in the flash's test bulb cover so that the prop could be hung from a hook on Luke's belt.
A convex, chromed dome with a hole in the center was added onto the top end of this droid caller prop. The origin of this piece is unknown.
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