This 4 channel stereo headphone amplifier is designed for all types of headphones, it allows 4 people listener simultaneously and setting volume independently, its high-power stereo amplifier ensures highest sonic quality even at max. volume, ultra low noise 4580 operational amplifiers provides you outstanding audio performance. Features: Super-compact 4-channel stereo headphone amplifier applied for studio and stage. Features 4 headphone output channels and 1 input channel. Each output channel with volume control for setting volume independently. Highest sonic quality even at maximum volume levels. Ultra low noise 4580 operational amplifier provides you outstanding audio performance. 12V DC power adapter included, with light for indicating power on. Specifications: Material: Metal Color: Black Power Adapter: US Plug Voltage: 12V(Out); 110-240V(In) Input Jack: 1/4'' TS Connector, Stereo Output Jack: 1/4'' TRS Connector, Stereo Item Size: Approx. 10.5 * 5.7 * 4.7cm / 4.1 * 2.3 * 1.8in Item weight: 186g / 6.56ounce Package size: 141 * 144 * 101mm / 5.55 * 5.67 * 3.98in Package weight: 365g / 12.87ounce Package List: 1 * Amplifier 1 * Power Adapter 1 * User Manual (English)