Built-in amplifier electric guitar. Sound is produced by inserting a 9V square dry cell battery and pulling up the volume knob. The volume knob is not original. As the volume is increased, distortion gradually occurs. The built-in speaker, external output jack, and headphone jack all function well, with no scratchy noise. Neck is straight. Frets are 80% remaining. No dead spots or buzzing. There are some dents (see photos). Please understand that this is a used item before purchasing.