The LEF-10C is a selective calling open voice style master station, used to answer calls from other remotes or masters. The system can be designed to include any combination of master and sub stations. The LEF-10C has the ability to communicate with ten other stations, selectively release doors, plus make an All Call and/or receive background music.

Incoming calls from a sub or door station sound an electronic tone and light an LED, remaining lit for approximately 20 seconds. Communication at the calling master is press-to-talk, release-to-listen, and is hands free at the responding station. The person at the master station can selectively call and talk with a person at any other sub or master station in the system. The privacy feature on the master prevents eavesdropping from another master station. An All Call announcement can be made from the master if the system includes the All Call/Chime Adaptor.