Switching between breast and bottle is second nature with Closer to Nature Teats. Designed in conjunction with breastfeeding experts, the revolutionary new tommee tippee® Closer to Nature teat mimics the natural flex, movement and softness of a mum?s breast, to make switching between breast and bottle easier than ever before. The unique shape of the Closer to Nature teat encourages your baby?s natural feeding action so that switching between breast and bottle becomes second nature. Compatible with all Closer to Nature Easi-Vent Bottles.Teat collapse resolutionThere are two reasons a teat may collapse. One is an indication that your baby is ready for a faster flowing teat and may be sucking so hard that the teats can not release the air fast enough and collapses. The other is that the Closer to Nature Easivent teats are made from very soft silicone, therefore over time the silicone can remould when not in use, for example when on the shelf in store.You will have noticed a small tent-like vent on the inside of the teat - this should have a small slit along which allows the airflow through the bottle, and if this remoulds it will cause the teat to collapse during a feed. Please see the diagram below that may help, which is also highlighted on the front of the instructions.All you need to do to rectify this problem is to rub the valve between your finger and thumb until the slit re-opens. You will only need to do this once and the teat should then function as normal.DirectionsOnly suitable for use with tommee tippee closer to nature bottles. Important instructions are included inside. Please read and retain for future reference.Box Contains2 x Closer to Nature Slow Flow TeatsManufacturer Contact InformationMayborn Group, Northumberland Business Park West, Cramlington, Northumberland, NE23 7RH, UK.