Due Fili electronic unit for audio entrance panel, up to 200 internal units, for 1200, 1300, 3300, 8000, 8100, Patavium and letterbox 2550/x cover plates, can operate individually, as a master entrance panel, without other electronic entrance panels, up to 2 entrance panel call buttons can be connected, for a greater number of buttons use additional modules 8051, 8052, 8053, 8054 in 8000 entrance panels or module 693P in other entrance panel models
