I don't know if it works, my cousin just bought me one and it's more effective than dh doing massage. I feel the burn around 5 cms, so I still have a ways to go with it, I'm under the impression the balloon goes to 10cm but maybe I'm wrong. Worth trying in my eyes I'd prefer to do something that might help than to do nothing. I'm assuming it will help with being familiar with the sensations of crowning too.