It does one modulation effect at a time,
However some of the modulation effects are a combination of a number diiferant effects mixed together like the undulator which is a combination of delay,reverb etc.
It works in sets of banks like a most multi FX stop boxes but you can only activate one at a time per bank.
Its a great box with a particularly amamzing Chorus and Wah which can be controlled with an external pedal.
Here is a list of what it does -
[list]
[*]Chorus (Four Types)
[list]
[*]Liquid Chorus
[*]Shimmer Chorus
[*]Organic Chorus
[*]Classic Chorus
[/list][*]Phaser (Five Types)
[list]
[*]Negative Phaser
[*]Postive Phaser
[*]BiPhase Phaser
[*]Feedback Phaser
[*]PhaseX0 Phaser
[/list][*]Wah (Four Types)
[list]
[*]WahWah Q-Wah
[*]Voc-Wah Q-Wah
[*]Bass Wah
[*]Bass Vocal Wah
[/list][*]Flanger (Five Types)
[list]
[*]Positive Flanger
[*]Negative Flanger
[*]Jet Flanger
[*]Thru-o Flanger
[/list][*]ModFilter (Three Types)
[list]
[*]Lowpass ModFilter
[*]HiPass ModFilter
[*]BandPass ModFilter
[/list][*]Rotary (Two Types)
[list]
[*]Standard Rotary
[*]Giant Rotary
[/list][*]Tremolo (Two Types)
[list]
[*]Bias Tremolo
[*]Opto Tremolo
[/list][*]Vibrato (Three Types)
[list]
[*]Modern Vibrato
[*]Vintage Vibrato
[*]Retro Vibrato
[/list][*]Undulator (Two Types)
[list]
[*]Pitch Undulator
[*]Feedback Undulator
[/list][*]Ringmod (Two Types)
[list]
[*]Ring (DC) Ringmod
[*]String (AC) Ringmod
[/list]
[/list]