Controls “Level” controls volume (right is louder, left is quieter). “Sustain” controls the amount of compression/sustain from the circuit (right is more compressed/sustained, left is less compressed/sustained). When activated, the side push switch toggles between two modes: Vintage and Bright. Bright mode helps your guitar cut through the mix when you need a little extra clarity for darker pickups or amplifiers. The footswitch activates the pedal via soft touch bypass switching. The status LED indicates the circuit is active. Specs The ¼” input and output jacks connect to your guitar and amplifier. The power jack accepts standard 9V DC Negative Center power and consumes 37mA.