• All Call to Standard LE Series Sub Stations

• Eliminating Call Tone from Sub Station at LEF Master Station

• Increase timing circuit of call-in LED

• Installing Volume Control on LE Series Sub Station

• LED Monitoring Indicator on an LE Series Sub Station

• Separate Transmit and Receive Volume Controls on LEF Series Master Station

• Tape Recorder Output on LEF Master Station

• Using Relay Contacts with the LEF Series