Avent Silicone Nipple is for a thick feed flow and is meant for babies who are 6 months or older. This product also features an anti-colic valve that is meant to release air from your child's stomach to release air and lessen the colic. The nipple has a ribbed design and the shape allows a secure lock so that the nipple doesn't collapse and your child remains at peace. It also has a special design that makes it easy for the baby fit in their mouth and nibble. This product is BPA free and can be easily washed with water to kill off all the germs and bacteria before letting your child use it.