Description:This headphone amplifier is characterized by high/low gain switch, which enables it to allow you to make a better sound effect and achieve the best headphone performance.What this headphone amplifier can offer you are compact size and aluminium alloy surface, so it can achieve long term use and is easy to carry.Made of premium aluminium alloy material, it is firm and durable to use.The length of the product is 11.2cm, the width is 6.2cm, and the height is 11cm.It is compatible for Sony, for Sennheiser, for Sennheiser RS120 and for Beyerdynamic.Item Name: Headphone AmplifierMaterial: Aluminum AlloyAudio Input: 3.5mm JackAudio Output: 3.5mm JackLoad Impedance: 16-300 Features: Low Noise, Gain Switch, AdjustableSize Details: 11.2cm x 6.2cm x 1.1cm/4.41" x 2.44" x 0.43" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Headphone Amplifier1 x USB Cable1 x Audio Cable1 x User Manual