Used as duplex door phone as well as inner intercom.
Built-in digital circuit and microcomputer- controlled circuit. One outdoor unit can call 2-3 indoor units for duplex intercommunication. Any indoor unit can call 2-3 other indoor units Each indoor unit can have confidential talk with the outdoor unit.
Clear intercom without noise.
The talking distance is less than 150m.
4 wires for connecting all the units.
Electronic-lock release function.
The outdoor unit meets IP44 water-proof standards.