This is in our top 5 of the baby !! Boiling water put in it is still hot and warm 12h later 24 hours later. We put water in the white thermos container was dipped his bottle for about 3 minutes and the bottle is ready to give baby. Hot water is put back into the thermos and may tank completely for at least another bottle.
We are parents of twins and thermos saved us on numerous occasions, including walk when we do not necessarily enough to warm a bottle.
As against it weighs heavily filled (of course) and takes up space in the diaper bag.