The Duality Fuzz from Darkglass Electronics is a unique fuzz pedal designed for bass. It's actually two fuzz circuits that you can blend together using the duality knob. One of the fuzz engines is a gated, sawtooth fuzz and the other is a tight, high-gain fuzz. Internally, there is an easily accessible filter control and blend control for further tone-shaping.

This example shows a small scuff on the front of the pedal.