Samonsite bubble travel cots - ok for 4 month old?

[milklady]

I've just ordered one of these, which says they're suitable from 6 months. I didn't want to bother going for the bassinet type one as DS is very tall and I'd probably only use it once before he outgrows it.

Has anyone use this for a younger baby? Does anyone know the reason why they say from 6 months on this one?

I think is until the baby can sit unaided (and is likely to wander out of the cot on his own accord)

bump