The Ultra Tremolo UT300 Classic Tremolo Effects Pedal by Behringer produces warm, classic tremolo effects modeled after vintage amps from the 1960's. It creates a fresh, new take on the distinct Tremolo sounds heard on countless surf records throughout the decades while providing simple, easy to use operation. Three dedicated Rate, Wave and Depth knobs allow you to effortlessly shape and customize your sound. It also features a cool, blue LED indicator letting you know if the effect is on or off while doubling as a battery check. An electronic On/Off switch is used to achieve the highest signal integrity when in bypass mode while quality components and rugged roadworthy construction ensure long-lasting durability. The UT300 operates on a single 9 volt battery but can also be powered by Behringer's optional DC power supply. Features Produces warm, classic tremolo effects modeled after vintage amps from the 60's Dedicated Rate, Wave and Depth controls allow you to shape and customize your sound Blue status LED indicates if the effect is on or off and doubles as a battery check Operates on 9 volt battery or optional Behringer PSU-SB DC power supply Electronic On/Off switch for highest signal integrity in bypass mode Quality components and rugged roadworthy construction ensure long-lasting durability Specifications Pedal Type: Tremolo Inputs: 1 x 1/4" Outputs: 1 x 1/4" Power Source: 9V DC power supply (sold separately) Batteries: 1 x 9V Height: 2.125" Width: 2.75" Depth: 4.8" Weight :0.73 lbs.