Free of Bisphenol-A (BPA), Phthalates, Nitrosamines, Lead, PVC, PET, and biologically harmful chemicals, these bottles feature no-spill spouts and are perfect for young ones from 9 to 36 months of age. Most of the sippy cups on the market have hard plastic spouts or rubber spouts. Thinkbaby built the Thinkbaby Sippy Cups with soft silicone spouts. This makes for easy transition from baby bottles to sippy cups. This is a struggle that most parents face in moving to the next stage of feeding. With the Thinkbaby Sippy of Steel, the little one is already used to the feeling of a silicone spout, so making the transition is quite simple.