The White bit is a bit too small, my baby was born small and didn't need it. It's more prem size. But still worth having in general for the blue bit which is slightly too big for my one month old but ok and does look and feel nice. You can move it up or down to reach your babies head height.

My newborn didn't need the white inner for her car seat, even on the day she was born. However is good to have it as a prem baby would need it. This is a great thing to have as it gives you peace of mind that your babies head is stable in her (or his) carseat or pram. I have one in her pram and one in her carseat. I recommend this and I think my daughter would too. She doesn't grizzle with it, she just falls to sleep.