REVERB: The spring reverb sports a dwell circuit that gives it nearly bottomless depth and a Mix control for wet/dry. BUFFER: A buffer is an active electronic circuit that keeps your guitar signal strong and preserves the frequencies of your guitar sound. OVERDRIVE: The overdrive has a drive knob, a tone knob, and a level knob. knob adjusts gain, the tone knob adjusts treble and the level knob adjusts the output volume of the pedal. BOOSTER: Put the booster in line with any effect to provide boost and definition. Improve the gain and saturation of your amp. BOOST Knob, Adjusts the amount of boost. DELAY: The delay is a natural sounding digital/analog delay, with the analog direct signal path. Specifications: Power Supply: DC 9V power adapter (not included) Item Size: 23 x 6.8 x 3.8cm / 9.1 x 2.7 x 1.5in Color: Green Material: metal Package Contents: 1 x Guitar Effect Pedal Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.