There is a speed dial at the base of the Rockit. Turn it clockwise to increase the speed and anti-clockwise to reduce the speed. Slowly change the speed until you notice the most rocking. It may not be the fastest speed - often you can get a nice rock at lower speeds if you hit the sweet spot (resonance frequency) of your particular stroller / pram.
Mounting the Rockit high on the frame or top handle will also allow you to generate a nice rock at lower speeds.
