Philips Avent

I used avent bottles for both my children. The teat sizes are only recommendations, Not that you must change according to that particular age. I remember my kids had to wait for a bit longer before they were ready to increase teat size as they ended up gagging on the increased flow. If you notice baby has trouble coping with the faster flow of milk, feel free to go back to 0mth size teat and try again a few weeks later.