The Electro-Harmonix White Finger is an all-analog optical compressor pedal using the same style of compression as the Black Finger tube compressor and studio-grade NY-2A, but swapping tubes stages for FETs to bring it in at a more affordable price. Two switchable optical sensors, LED and Lamp, offer up different compression curves -- slower and gooier on the "Lamp" setting and faster with the "LED" setting. Flip on the "SQUISH" function while in Lamp mode for a longer attack time and more heavy compression that's killer on keys and chords.