My girl was already 12 weeks old when we purchased ours. I was hoping it would be helpful prior to her starting physical therapy for torticollis. She screamed her head off every time it was on. It was not a cry or scream I had heard before and it was brutal. I kept trying it and tried to make it fun and give her lots of breaks, but she wanted to move her neck freely and would have it any other way. I think if I had gotten this when she was 8 weeks old or younger it would’ve been much more smooth since babies just don’t have as much strength yet.