Two family doorphone COSMO, black

Analog CYFRAL intercom sets are widely used, however, they are most often installed in single-family houses, small enterprises, but also in public use institutions The COSMO doorphone uses a duplex signal transmission, and the uniphone is connected to the call panel with a two-wire line. This line transmits the following signals: call (bell), acoustic (speech) and the signal controlling the electromagnetic catch.