Born Free The Safe & Smart Bottle - Soft Silicone Nipples: The BornFree nipples are extremely soft and gentle for your baby to suckle and are available in 5 flow rates to suit babies from 0-18 months. Due to the unique BornFree valve, the nipples prevent the hard suckling needed with conventional bottles. The Revolutionary Inner Valve And Air Vent: The new innovative air vent helps eliminate colic symptoms such as gas and spit-up by reducing the build up of vacuum and is also medically acknowledged to reduce the risk of middle ear infection. The unique inner valve prevents side-leaks, and unlike other vented bottles, allows you to shake freely when mixing. Safe Bisphenol-A Free Plastic: BornFree is made of a new, safe, honey-colored plastic called PES (Polymer) that is free of Bisphenol-A. BornFree's special plastic is also more resistant to detergents. Tested And Proven!: In a recent independent test, various leading brands of bottles were tested for the level of vacuum (negative pressure). The more negative pressure, the harder it is for your baby to feed. The BornFree bottle was proven to have the lowest vacuum level making it the easiest way for your baby to bottle feed in combination with our very soft range of nipples.