PBM-15: UL Listed. Our two channel contractor series mixer/amplifier is a 15 watt amplifier. It features an auto mute function, music on hold output with separate level control (600 ohm line and one watt 8 ohm), 600 ohm telephone line input with level control, bass/treble toOur two channel contractor series mixer/amplifier is a 15 watt amplifier. It features an auto mute function, music on hold output with separate level control (600 ohm line and one watt 8 ohm), 600 ohm telephone line input with level control, bass/treble tone controls, front panel level controls, and manual muting contacts. In addition to the telephone line input, this unit accepts inputs from two sound sources. Each source utilizes a microphone input (terminal strip). Source 1 also offers the option of an auto summing stereo auxiliary RCA input. Outputs include a choice of 4, 8, and 16 ohm as well as 70 and 25 volt line outputs. Rack (PBM-RK1) and wall (PBM-WK1) mounting kits are available (not included). Technical Specifications Finish Black Frequency Response Rate 50-15,000 Hz. +/- 3 dB Input Sensitivity/Impedance Tel: 100mV/600 ohms, unbalanced Mic-1-2: 1.0mV/600 ohms, balanced Aux- 1: 200mV/50,000 ohms, unbalanced Music on Hold 600 ohm line/1 Volt 8 ohm/ 1 Watt Mute Level Aux 1/Mic 2 >/= 40 dB Power Supply 120 VAC, 50/60 Hz. Rated Output Power 15 W RMS S/N Ratio Mic- 1-2: Better than 55 dB Aux- 1: Better than 70 dB Tel: Better than 60 dB Speaker Outputs 4 ohms, 8 ohms, 16 ohms, 25/70V line Tone Controls Bass +/- 10 dB at 100 Hz. Treble +/- 10 dB at 100 Hz. Total Harmonic Distortion 1% or less at 1 kHz. VOX Level Mic 1/Tel 0-40 dB adjustable Other models availabe: PBM30, PBM60 & PBM120. Choose link below for specifications of each model.