Pro Intercom MS300 Master Station 3-Circuit Intercom OnlyThree circuits rather than the usual two Each circuit can be Intercom or IFB in any combination Circuits linkable, A+B or A+B+C, with front panel switch Each circuit may have its termination circuit lifted via rear panel DIP switch Independent level control of program audio for each circuit, with an LED VU meter for each Mic switch on each circuit can be quickly tapped for locking or held and released for momentary Internal power supply is internal,