The Canton Combi 40 R is a switching unit and program selector designed for use in audio applications. Manufactured in Germany between 1978 and 1984, this model features a sleek metal silver and plastic black design. It offered users a versatile way to manage their audio sources effectively. The original retail price was approximately 140 DM. This unit is part of a larger series that includes several other models such as the Canton Combi 30, Combi 30 R, Combi 40 mix, Combi 40 T, and Combi 70 variants, each designed to meet different audio needs and preferences. The Combi 40 R stands out for its functionality within its product line, catering to user requirements for audio management during its production period.