This stereo headphone amplifier can be widely used with your mobilephone, computers, DVD and other deivces. Both the input and output are 3.5mm audio interface. If you are interested in this product, come and have a try, it will not let you down. Features: The volumes of each channel can be adjusted independently, you can adjust the volumes according to your needs. There are 10 output channels for you to use, which can meet your most needs. This tool will maintain the highest sonic quality even at maximum volumes levels, giving you a better using experience. This compact headphone amplifier system for wide applications, you can carry it easily. The audio output can connect to your headphone or your passive speakers. Specifications: Material: metal Type: without power adapters, EUPlug, USA Plug (optional) Working power: Direct current 12-24V Input impedance:10K Gain: 12dB Output impedance: 16-600 ohms Input and output jack: 3.5mm Item size: 230 * 73 * 30mm / 9.1 * 2.9 * 1.2in Item weight: 440g / 1.0lb Package size: 250 * 150 * 46mm / 9.8 * 5.9 * 1.8in Package weight: Without power adapters: 541g / 1.2lb With power adapters: 614g / 1.4lb Without Power Adapters Packing List: 1 * Headphone Amplifier 1 * Cable OR With Power Adapters Packing List: 1 * Headphone Amplifier 1 * Cable 1 * Plug (EU, USA optional)