This telephone set has type number КД-6 (KD-6 in English), and was made by Krasnaya Zarya, one of the few telephone manufacturers in the Soviet Union, and Russia previously.

The KD-6 was a 6-line "concentrator" telephone set intended for senior managers of the central banking system, or perhaps other large organizations. The manual explicitly refers to the banking system.  A similar companion set, the КС-6 (KS-6 in English) was for use of the manager's secretary. Contributed by Harry Smith and Karl Brose. Processed by Paul Fassbender.