Backed by over 60 years of research into babys natural sucking behaviour, the upgraded Pigeon SofTouch nipples/teats come with researchbased latchon line on the teat for appropriate latching, and even softer nipple that is closest to mothers breast. Developed to functionally mimic the feeding movements that babies perform when drinking from mums breasts, SofTouch Nursing or Baby Bottles are crafted to especially support breastfeeding mums to feed their baby from both breast and bottle seamlessly. Anticolic with advanced air vent system that minimises swallowed air as baby drinks. Contains: 2 x teats of size LL, for 9+ months. The opening of the nipple is slightly bigger Ycut than L size nipple to allow more milk to drip out. Milk drips out when theres pressure on the nipple. This helps babies to control the flow of milk and train their sucking ability as babies at this age have developed a stronger jaw muscle. How often should you replace the bottles teats? For the silicone nipple, rotate the use of 2 or more nipples for about 2 months before replacing them (using boiling, steam, and chemical sterilisation). If you see any stubborn milk stains, scratches, or discolouration on the Nipple, it is an indication to consider changing to a new nipple.