Flex FX - Version 1.2 The Flex FX VST plugin package contains 6 different effect plugins, the Amplitude Modulator, the Chaotic Lowpass Filter, the Chaotic Highpass Filter, the Ensemble effect, the Stereo Feedback Delay and the Fat Resonator. Each effect can be used as an insert or send effect. All, except the Ensemble, have their own dedicated LFO (Low Frequency Oscillator), which can modulate the effect. The LFO can be synchronized with your host (sequencer), provided that it supports sync.