Actually one of the best things my wife and I ever bought to help our little fella get some zzz’s.
We leave it by his feet in the cot and just press once for the first setting. sometimes we set it higher when he’s unsettled. We don’t need the light function coz we already have an illuminating diffuser that we set to red in his room. We know he sleep good with it because he naps really well from the vibration in the car.