Ok, so I don't know what kind of magic is in this suit, but it is better than Merlin himself. My little one is going through a growth spurt and has been waking 4-6 times each night. I just got this thing yesterday. Washed it. Put it on him last night at bedtime. He didn't wake up once. Not once! OMG. I'm a believer! I don't know how it works, but best $40 spent.