Digital Modulation pedal with Chorus, Vibe, Phaser and one user memory slot. The Black Sheep Roto Engine is a "three in one" modulation pedal to cover most needs for any guitarist. With the flick of a switch you can choose between three classic modulation effects, Chorus, Vibe and Phaser. The controls Level, Speed and Intense are simple to use when dialing in your sound. All Black Sheep Digital pedals have one user memory slot. Just set the sound you want to save, press and hold the footswitch, and the sound is saved. You can then double click the footswitch to toggle between your saved sound and another sound that you have dialed in on the pedal. This is a feature not at all common amongst stompboxes, but really great to have! Roto Engine is an excellent Modulation pedal which will certainly expand your sound arsenal, generating a whole range of cool modulation effects. The Black Sheep Rotos Engine is a compact, true bypass, sturdy built pedal that delivers a plethora of great sounding modulation effects at an affordable price.