Behringer MDX4600, Reference-Class 4-Channel Expander/Gate/Compressor/Peak LimiterCondition:* Used, Removed From Service In Working Condition.* Tested Fine For Basic Operation. As Pictured.Additional Notes:* Switchable IKA (Interactive Knee Adaptation) program-adaptive compression circuitry combines the advantages of hard-knee and soft-knee characteristics* IRC (Interactive Ratio Control) expander/gate circuitry for virtually inaudible noise suppression* Switchable dynamic Enhancer for brilliant, lively audio even with heavy compression* IGC (Interactive Gain Control) peak limiting circuitry combines clipper and program limiter for reliable and inaudible protection against signal peaks* Switchable Low contour filter prevents “pumping” due to low-frequency dominated compression* Stereo couple function selectable for channels 1/2 and 3/4* Separate 8-segment LED meters for input/output levels and gain reduction* Selectable operating level (+4 dBu/-10 dBV)* Servo-balanced inputs and outputs with ” TRS and gold-plated XLR connectors* Internal switch-mode power supply (100 – 240 Volt AC) for noise-free audio and low power consumptionBehringer MDX4600