I purchased this for practice about three years ago and used it a few times. There are scratches. Product Description The mobile headphone amplifier BIGHEAD is a new, multi-functional product that can be used in a variety of ways: as a high-performance headphone amplifier for bass, as a portable headphone amplifier for audio that dramatically upgrades the sound quality of smartphones, etc., and as an audio interface when connected to a computer via USB, with a maximum input/output of 16-bit/48kHz. Product Specifications Model: BIGHEAD Output: 200mW (100mW + 100mW) EQ: Treble, Bass Input/Output Terminals: Instrument input (mono phone jack), line input (stereo mini jack), digital input/output and power supply (micro USB connector), headphone output (stereo mini jack) Audio Interface Function: Supports input/output up to 16-bit/48kHz sampling rate Power: Built-in lithium battery Dimensions: 65(W) x 25(H) x 135(D) mm Weight: 240 g