Features: 1 Input 2 Outputs: Supports 1 auditory input and 2 auditory outputs to meet the needs of multi-device connection. Pre-amplifier: enhances the output effect of auditory signal and improve the sound quality. Equipped with 3.5mm volumes control knob, convenient for users to adjust the sound. Stereo Music: Enables stereo music auditory signal processing for a more immersive auditory experience. Headphone Amplifier: Built-in headphone amplifier allows you to connect headphones to enjoy more powerful auditory output. Compact design: Compact board design, suitable for installation in a variety of auditory equipment, space-saving. Specifications: Item: 1 Input 2 Outputs Headphones Amplifier Model：AU~102 Component： Metal Size：about 8.3x5.3x2.4cm/3.27x2.09x0.94in Power： DC5V Package Includes: 1Set 1 Input 2 Outputs Headphones Amplifier note: Due to the problem of lighting effect and shooting, there might be tolerances in product, please understand. Please allow 1cm errors due to measurement