Feature 1 METAL MATERIAL: This small headphone amplifier is made of premium metal material that is rugged and durable for long lasting use. 2 LOW NOISE: The low noise 4580 op amp ensures excellent sound performance and the high power stereo amplifier ensures maximum sound quality at maximum volume. 3 8 CHANNEL: Headphone amplifier features 8 independent channels, each switchable, with adjustable volume for each channel. 4 INDEPENDENT CONTROL: 8 monitoring devices can be used at the same time, each device has an output volume control, easy to adjust the ideal monitoring volume. 5 COMPACT AND PORTABLE: This stereo headphone amplifier is designed to be very compact and portable for use anytime and anywhere.Item Type: Headphone AmplifierMaterial: MetalPlug Voltage: 100-240VInput:Type: 1/8in TS Connector, StereoImpedance: 100kMaximum Input Level: + 15dBuOutput:Type: 1/8in TS Connector, StereoImpedance: Approx. 80kMaximum Output Level: Approx. 40mW in 100 Package List1 x Headphone Amplifier1 x Power Adapter 1 x Instruction Manual