Flang-3R is a free 6 band stereo flanger effect, You have control over the modulation with the standard osc shapes and Sample and Hold also. Theres feedback which brings out the sound more and dampening and mix if you want just a slight effect and shift to adjust the tone. Theres 3 different modes for the speed controls and you can sync the modulation, use linked control amounts or adjust the left and right separately.