Soft and flexible nipple: For seamless switch between breast and bottle.
Food grade PPSU material: BPA free,safe and environmental friendly.
PPSU (Polyphenylsulfone) is a type of high performance polymer. It is a plastic but has the benefits of glass which is a perfect material for baby bottles. It is incredibly durable, temperature and fall resistant. Which does not absorb odor or color and you can sterilize without any deformation.