Whirlwind PB06 1 Line In to 6 Mic Out Passive Press Box Whirlwind PB06 1 Line In to 6 Mic Out Passive Press Box - Whirlwind 3 Year Warranty 1 to 6 line in/microphone out passive pressbox expander for broadcast and business conference applications Rugged, all-steel housing with convenient carrying handle Transformer isolation and grounding for each output eliminate interchannel and RF noise