Nady Guitar Effects Pedal 4 Pack Bundle &ndash; Tubescreamer &ndash; Tube Amp Simulator &ndash; Flanger &ndash; Tremolo &ndash; Classic Analog Stompbox Sound &ndash; Portable All Metal Casing &ndash; 9V Battery or Adapter Operated Pronounced design with accurate emulation of the most popular guitar effect sounds. Warm tube tone to rich flange and tremolo sounds - Perfect for all styles from blues to heavy metal Versatile in both sound and function  Tone and effect shaping is a breeze with highly-responsive dial knobs All-metal casing for years of roadworthy reliability Operates with one 9V battery or the optional PAD-1 AC adapter