"The Whirlwind PressMite 1 Line In to 12 Mic/2 Line Out Active Press Box provides a 60 dB gain adjustment for one mic or line input. It also features a built-in headphone amp. Two alkaline 9 V batteries provide power for typically more than 8 hours of continuous operation, monitored by a Battery OK LED. The batteries are easily replaced via side-mount trays. In MIC input mode, 18V phantom power is selectable and a three segment LED headroom display speeds level adjustment. If more outputs are needed, PB Series Press Boxes can be connected to the line outputs to provide up to 48 additional mic outputs. The PressMite's box is built to withstand the abuse of public events.|1-in/12-out Active press box with phantom power and high isolation between outputs|Rugged steel metal enclosure|Headphone amp with separate volume control|Dual 9V battery or DC power supply operation for enhanced portability|Expandable though line out connection to 48 total outputs|3-segment headroom monitoring LED display"