Pur advance slim neck bottle has a pro-flo unique anti-colic bottle system which reduces air swallow during feeding and helps to reduce tummy troubles. Gentle touch nipples is made from extra soft silicone. The nipple is ergonomically designed to mimic a mothers breasts which soothes the baby while feeding. Pro-flo is a unique anti-colic baby feeding bottle value system with in-built air chamber which enhances the drinking performance by initiating the air intake faster than similar products; therefore allowing a balance flow of liquid with the minimum suction effort. Bottle is made of quality food grade material and free from bisphenol-a chemical (bpa free) which is safe for baby.