Item Type: Stereo Headphone Amplifier Material: PCB Power Supply Voltage: (DC12-24V) (Without Adapter) Input: AUX Output: 3.5mm Static Current: 85ma Gain: 12db Output Impedance: 16-600 Ohms Package List 1 x Stereo Headphone Amplifier 1 x Sound Cable 11 x Knob 110 Channel, High Power: 10 channel stereo headphone amplifier splitter with 4 high power stereo amplifiers, each with output level control. 2Compatible: The stereo headphone amplifier splitter is compatible with 3.5mm headphones and 6.35mm headphones, you will need a 3.5mm to 6.35mm adapter. 3Power Supply: The stereo headphone amplifier splitter is compact and flexible, and can power up to four pairs of headphones and up to ten individual volumes (without power supply). 4Upgraded Design: Upgraded stereo sound amplifier design with power switch and 3.5mm headphone output. Suitable for studio and stage applications. 5Independent Output Volume Control: The stereo sound amplifier can power any headphone with independent output volume control.