1) Food grade BPA free liquid silicone + PP material, more safety, environmental and healthier. 2) High stability, acid-resistant and alkali-resistant, will not generate harmful substance to human health. 3) Soft liquid silicone body design, convenient to feed and hold, will not hurt baby. 4) Food grade soft liquid silicone rubber nipple, odorless, it’s double thickness than common nipple, easy to accept by baby. 5) Similar to breast uplift design, encourage baby to open mouth to suck milk, make the movement of baby’s tongue and mandible same as the suction from breast, and feed as per the same frequency of suction from breast. 6) With super strong extension, the nipple can extend by 6cm length during suction, fit for the baby’s lactation nest.