The Jitter Loop is an effects looper with random function added. The switch knob controls which loop is active. You might just bridge 1 to 1 (as defaulted) and have another effect, like a delay, inserted between 2 and 2. Turning up the Jitter knob a little will cause the loop to switch randomly between 1 and 2. The Slew knob tames the randomness causing the switching to become sluggish.