Pro Intercom MS301 Master Station 3-Circuit Intercom & IFBThe MS301 master station has 3 channels, operated independently or linked in A+B and A+B+C modes. IFB is available on any channel. Front panel XLR allows for a headset, handset or goose neck microphone. Powers up to 66 stations. Three 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