Item Type: Headphone Amplifier Material: Iron Shell Input: Type: 1/4 Inch TS Connector, Stereo Impedance: 100k Maximum Input Level: +15dBu Headphone Output: Type: 1/4 Inch TS Connector, Stereo Impedance: 80k Maximum Input Level: 40mW In 100 Voltage: 100-240V Package List 1 x Headphone Amplifier 1 x Instruction Manual 1 x Adapter 1PROVIDES MAXIMUM FLEXIBILITY: Mini Headphone Amplifier is designed for use with all types of headphones, offering maximum flexibility. 2ULTRA LOW NOISE: 4 channel stereo headphone amplifier operates with the ultra low noise 4580 to ensure excellent sound performance. 3INDEPENDENT OUTPUT LEVEL: Headphone amp amplifier utilizes 4 channels to set independent output levels for a wide range of listening needs. 4INDEPENDENT VOLUME CONTROL: Headphone amplifier achieves maximum sound quality even at maximum volume. Volume of each output channel can be controlled independently. 5RANGE OF APPLICATION: 4 way headphone amplifier is an ultra compact stereo headphone amplifier for studio and stage applications.