It ensures the continuity of the peristaltic movement of the baby while sucking on the mother, thus allowing the baby to pass from the bottle to the breast - from the breast to the bottle. it is made of safe bpa and bps-free polypropylene to store food. with avs air inlet system technology, air enters the bottle and the potential cause of colic is air. the reason for swallowing is prevented. it is compatible with all lansinoh pumps. returns are not accepted for the opened product. Improved version for clearer understanding and better search visibility. Suitable for users seeking detailed and reliable product information.