CITY-DUOX Doorphone Kits incorporate the latest digital technology from FERMAX. DUOX is the new digital system that represents a technological and innovative leap in the market. It only requires two non-polarized cables for: power, audio and data transmission. Includes: 70704.- CITY DUOX 1/L plate. S1 plate: 130x128mm. 8948.- S1 kit embedding box: 115x114x45mm. 3430.- iLOFT DUOX telephone. 4810.- 18VDC/1,5A-12VAC/1,5A power supply. DIN10. 3244.- DUOX filter.