Ultra-compact stereo headphone amplifier for studio and stage applications. With 8 headphone output channels and 1 input channel. The volume of each output channel can be controlled independently. Provides the highest sound quality for each earphone even at maximum volume. Ultra-low noise 4580 operational amplifier with outstanding performance. Comes with a DC 12V power adapter. Input type: IN (O IN) Output type: OUT (O OUT) Built-in battery: None Recommended headphone maximum impedance: 65-80 Ohm Type: Mini Amplifier Model: HA800 Product weight: 350g Plug Type: US Plug, it applies to Canada, , Mexico, Thailand, Taiwan, the , the Philippines and so on. Voltage:DC12V Colour:black Material:Metal Size: 19.6 x 5.7 x 3.1cm Package Contents: 1 x Amplifier 1 Adapter Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.