Page Port Preamp/ Expander is a solid-state audio preamplifier which can be mounted into a single-gang electrical box. The amplifier will accept a high impedance input (600 Ohms) and reduce it to a low impedance output. When the control knob is set on 5, the input signal level equals the output signal level. Capable of driving 150 Valcom one-way speaker/amplifier assemblies.- White Hardware.- Includes Surface/Flush Mount Box.- Boost Audio Levels For Up To 150 Valcom Speakers.- Add V-1094A's or V-2994-W's For Virtually Endless Expansion (150 One-Way Speakers Per Unit).- A Master Volume Control For Entire Systems Or Groups Of Remote Speakers.- Pre-Amplified Low Level Audio To Remote Sites.- Isolates Page Port From Speaker Lines.- Input Impedance: 600 ohm.- 24 Vdc, 45 mA.