I was at mums and babies this morning and they had like a toy that you put the baby on belly down and they have their tummy time on it. It was only small, it wasn't a roller as you actually put your baby lying on it instead of just shoulders and chest. It did spin when the baby kicked his legs but it stayed in one spot. That's as best I can describe it, I just thought it would be a good idea as my son is 4 weeks but hates being on tummy time on the floor. Thanks x