New CST2 Compressor & Sustain, completely redesigned, smaller size with the same incredible tones as always. Ideal for electric guitar, bass, and acoustic guitar. The CST2 Compressor & Sustain is a leveling pedal that acts on the dynamics of the sound produced by the instrument. It automatically compresses high-volume notes while amplifying low-volume ones. In this way, it can significantly increase the sustain time of the notes played.