I wanted glass bottles and new born baby bottles from other manufacturers were too quick flow. We have used as part of a mixed feeding, first the classic range and this range (since we wanted glass bottles). The bottles are sturdy, thick, honestly they are very good. Problem: when you put 210 ml of water, you have to go very gradually to bring the powder 7 pods otherwise it overflows !!! Unable to use these glass bottles for a quantity of 240 ml and the larger size does not exist. Too bad, if I had anticipated I would be turned me to another brand ... That said it is very suitable for the first 5-6 months if the baby makes 210 ml bottles.