Comforting Brown 1940s French 4.5cm Casein Buckle

A comforting cosy dark brown and and equally comforting cosy curvy design. 
4.5cm tall, and 4cm wide, gently curved for a perfect fit on your belt.
The inside aperture is just over 4cm tall.
It is made of casein plastic.
I found these in an old haberdashery warehouse -they are in excellent unused condition.