I’m using it!
Honestly, they claimed to be able to hold for 12 hours.
The longest I’ve brought fbm out was 12hrs during CNY.
I left it in the car while shuffling between houses. At around 6/7 hours, all of the milk melted 😩
The longest I'm out with my packit was about 8 hours, but with 2-3 reusable ice packs. The bag itself probably melted after 4-6 hours. I have 2 of them though, one for bringing milk to infant care and one to bring milk from work
Mummy J