Metal, I assume it is brass.

Measures 5 1/2" at the highest, 2 7/8" at the widest.  2 1/4" deep.   The inside box measures 3 1/4" high and 2" wide at the top, and 1 3/4" deep.

There is rust on the outer box, some old paint.   No major dings, dents, or any problems that I can see.   The latch on the inside window works well.

A10