Switchable AMPLITUDE or HARMONIC modes Emulates a Class-A tube amp circuit from end-to-end Gain control with auto level compensation Expression pedal control for SPEED Power Supply 9V – 18V, 2.1mm Neg. Tip Current Draw < 20mA Battery 9V, Included Chassis (in.) 3.2″ x 3.2″ x 4.9″ Chassis (cm.) 8 x 8 x 12.5 cm Finish Anodized Brushed Aluminum