Very Deco 1930s Czechoslovakian Textured Pressed Black Jet Glass 2 Part Buckle for 2.2cm Belt.

A striking Deco design different levels and surfaces, jet black glass.
Probably from the 1930s but maybe older.
It's 6cm long, 3.8cm wide, to take a belt up to 2.2cm wide
I just have 2.
CZECHOSLOVAKIA impressed on the back.
Czechoslovakia was formed in 1918  but the region of Bohemia and the Czech lands had been famous for glass production for hundreds of years (stating in the 1500s)