Loudspeaker intercom device `` UPG ''.
Everything else not included in the sectionsInterphone devicesSince 1980, the "UPG" loudspeaker intercom device has been produced by the experimental plant NPO "Volna". The UPG device is intended for two-way loud-speaking wire communication between two subscribers at a distance of up to 1000 meters. Rated output power 125 mW. Operating frequency range 450 ... 3000 Hz. Dimensions of one device 125x75x56 mm. Weight 450 grams. More details in the instruction manual.
