Moog Minifooger Analog Effect MF Trem.
 
It is based on a balanced modulator and Sub Audio VCO circuit, which allows it to generate harmonically-based swells, gallops, percussive rhythms and rotary effects that change with playing style and harmonic input. Also available are a wide range of classic tremolo effects, which dynamically react to your specific playing style. When pushed, the MF Trem will shift towards the sonic-origins of phasing and chorus. 
 For fine-tuned performance, plug in an expression pedal and conjure a wealth of beautiful, hands-free swells and rotary effects.