Nút nhấn chuông cửa AIPHONE DB-1SD –       The DB-1SD hands-free sub station features a call tone volume control with mute indicator, receive volume control, All Call button, Talk button, and Off button. –       It connects via 4 wires to the DB-1MD master station. Up to 4 sub stations can be added to this master and communication is possible between the 5 total stations via the All Call button. –       Máy […]