Feature:1. Made of iron alloy, headphone amplifier is sturdy and durable with a nonslip mat on the bottom to keep it stable.2. The ultracompact stereo headphone amplifier is easy to carry around and can be used anytime, anywhere.3. The 4channel distribution system allows up to 4 people to listen to playback at the same time with excellent audio quality.4. Independent volume control allows each listener to determine their own volume through a dedicated output volume control knob.5. 5 buttons ensure easy control; 1/4in and 1/8in output, 1/4in, 1/8in TRS and RCA input meet the needs of use.Specification:Item Type: Headphone AmplifierMaterial: FerroalloyProduct Size: Approx. 14 x 9.6 x 3cm / 5.5 x 3.8 x 1.2in.Package List:1 x Headphone Amplifier1 x Plug1 x USB Cable1 x User ManualNote:The product size is manually measured. There is an error of 13cm. Please refer to the actual product.