how long should nearly 7 mo old who can't sit unaided, sit in rucksack type baby carrier

[Gemmitygem]

we just got one of these rucksack style carriers where you can hike with the baby. The instructions say it should only be used for babies once they can sit unaided. DH is champing at the bit to use it. I would have thought it would be ok for a short walk e.g. 20-30 mins, but better to wait till he can really sit before using for a proper hike. DS is 6 and three quarter months and can't sit up unaided..

Any tips/advice much appreciated..

what kind of rucksack is it? brand?

it's a Deuter kid comfort III, blooming enormous!

they should only use door bouncers for 20 mins, is prob similar

those need for kids to be able to sit unaided before using. if you got an Ergo carrier, they don't need to be able to sit unaided and you may both get more use out of it in the long run.

door bouncers are different from those rucksacks.