Compact stack-type guitar amplifier MS-4, with adjustable gain, volume, and tone. - Model: MS-4 - Function: Guitar amplifier - Controls: Gain, Volume, Tone - Design: Stack-type design - Brand: Marshall Thank you for viewing. Sound output has been confirmed, and GAIN, VOL, and TONE are functioning. The main unit only. Please refrain from purchasing if you are concerned about minor details, as this is a used item. No claims and no returns are accepted.