Neewer&reg; NW-GP-1 Portable Mini Electric Guitar Plug Headphone Amp Amplifier (Classic British Distortion Effect) Classic british distortion effect guitar plug headphone amp amplifier Compact and light-weight design, easy to carry Designed with 3 knobs: level, Tone, Gain 6.35mm/0.25in plug, just plug into guitar jack, no need of installation Uses the phones jack to connect headphones, portable speakers, mixer or recorder