Check the listing for details. Vaddio EasyUSB - Pro Mic I/O 998-8520-000 Professional 4 Microphone Interface. Condition: Used. Listed at 236.00 USD. The EasyUSB PRO MIC I/O Interface from Vaddio allows you to use up to 4 A/V microphones in a PC conferencing system with the EasyUSB Mixer/Amp (sold separately). The front panel controls allow you to easily set the desired gain on the connected microphones with the help of four knobs and two indicator LEDs.The Dip switches on the rear panel allow you to control functions such as the low or high cut filter, phantom power (per microphone), and GPIO for mute status. It also features front panel lock-out to protect the knobs from being tampered with.The PRO MIC I/O features 3-pin female XLR connectors that allow you to connect table, gooseneck, or button microphones (sold separately). Each input channel incorporates an echo cancellation processing chain that is optimized for use with Unified Communications software applications such as Microsoft Lync, Cisco Jabber, Skype, WebEx, Vidyo, GoToMeeting, etc. Frequency Response: 20 Hz to 20 kHzDynamic Range: >90 dBTHD + Noise: < 0.02%Microphone Input : 4 x XLR female balanced microphone inputs 48 VDC Phantom Power Microphone Preamp-adjustable from 10 to 46 dB gainAudio Processing: Acoustical Echo Cancellation, Automatic Gain Control, Noise Reduction, Automatic Microphone Mixing, HP/LP FiltersUser Controls: Front Panel Rotatory Gain Controls, rear DIP Switches for audio processing and GPIO Ports: EasyMic Ports: 1 x RJ45 female proprietary interface (audio, power, & control), Maximum CAT5 Cable Distance: 100.0' (30.5 m) Control Port: RJ45 female Vaddio Std. RS-232 Pin-out for CAT5 cableOperating Temperature: 32 to 104°F (0 to 40°C) 273.15 to 313.15 KRelative Humidity: 20 to 80%Dimensions: 1.7 x 8.4 x 6.0" (43.7 x 212.7 x 152.4 mm)Weight: 1.4 lb (0.6 kg)