Check the listing for details. Clear-Com HB-704 Intercom Headset Station, 4 Channel. Condition: Open box. Listed at 325.00 USD. A surface mounted four-channel-selectable, full-duplex headset station, the Clear-Com HB-704 is designed for applications where speech intelligibility is a priority even in noisy environments. Equipped with momentary and latching LED talk switch, call tracking LED, Volume control and sidetone adjust that sets the level of the users voice in the headset, the HB-704 is versatile enough to fit comfortably into a wide variety of communication situations. ApplicationsTheatre / performance venuesBroadcast facilitiesIndustrial facilitiesFeaturesSelectable four-channel full-duplex communicationMicroprocessor controlled logic and switchingMomentary/latching talk switch with LEDVisual call signaling with bright LED indicatorHeadset connector with volume control and sidetoneadjustUse with optional TW or 4-wire circuit boardsEasy installation and connectionSpecificationsHeadset Microphone InputInput Type : DynamicInput Impedance: >=1K ohmMic Limiter Threshold: -2dBu ± 3dBMic Limiter Range: >= 15dBProgram Line InputInput Impedance: >= 5K ohmsHeadset OutputLoad Impedance: >= 8 ohmsOutput Impedance: < =25 ohmsOutput Limiter Threshold: +5dBu ± 3dBMaximum Output Level before Distortion: >= 17dBuParty Line OutputOff Noise: < -74dBuOutput Impedance: >10K ohmsParty Line InputCrosstalk: < -60dBMax level before Clipping: >= 12dBuFrequency ResponseHeadset Mic - Party Line: 300 - 15KHz ± 3dBParty Line - Headset Out: 300 - 15KHz ± 3dBMax DistortionHeadset Mic - Party Line: < = 0.5%Party Line - Headset Out: < = 0.2%NoiseHeadset Mic - Party Line: < -70dBuMax GainHeadset Mic - Party Line: 41dB ± 2dBParty Line - Headset Out: >= 34dBPowerInput Voltage Range: 20-30 VDCInput Current (Idle): < =50mAInput Current (Max): < =100mAInternal Adjustments and ConnectionsIntercom Line: Seven terminalconnectorOption Switches: Two DIP switchesOption Board Jumper: Two sets of options jumpersFront Panel ConnectorsHeadset: (1) XLR-4MFront Panel Controls & Indicators(1) Sidetone control(1) Talkbutton(1) Call button(1) Channel select switch(1) Volume controlEnvironmental: 32 - 122°FDimensions (W x H x D): 4.625" x 4.5" x 1.75"Weight: 0.46 lbs