Curta portable calculator 

Typ 1, 1950:
	rar first production series 
	Manufacturer: Contina Ltd., Liechtenstein. 
	rounded knobs and "System Curt Herzstark" character on the collar. 
	metal container with anti-clockwise opening lid. 
	
TYP 1, 1967:
	Manufacturer: Contina AG Mauren, Liechtenstein.
	plastic container, clockwise opening lid.