The 19” rackmount HM-400 4-Channel Headphone Amplifier offers an incredible amount of versatility and excellent sound quality in a single rack space. Perfect for professional applications including studios, Houses of Worship, practice spaces, and more. The HM-400 features a main input with level control plus stereo outs, aux inputs and EQ per channel with 12 total headphone outputs. 4-CHANNEL HEADPHONE AMPLIFIER -L/R Main stereo inputs L/R stereo outputs -7-segment LED metering per channel plus Main -3 headphone outputs per channel -Aux input on each channel with balance control to mix main and aux signal -Mute and stereo/2-ch mode switches per channel -12 total headphone outputs -"Built-Like-A-Tank" construction