The Carl Martin Ottawa is an envelope filter effects pedal that mimics the sound of your wah pedal without you having to step on a wah pedal and adjust those frequencies manually. It is ideal for solo and rhythm work, whether you are into the psychedelic '60s, the disco era of the later '70s, or any other music that requires this unique sound. Three included presets are High, Band and Low Pass filters, adjustments for bandwidth and attack as well as level and tone.