When we introduced the Thinkbaby line of baby bottles 95% of the baby bottles on the market were made of polycarbonate which contains BPA. Initially, we attempted to convince the major companies to move off of polycarbonate, but after being unsuccessful we launched Thinkbaby and Thinksport to address the concern of chemicals leaching from consumer products. We started with the baby bottle because polycarbonate was ubiquitous across the industry. As little ones systems are still in a state of development they have very little defense against foreign chemicals therefore, all of our bottles are free of - Bisphenol-A (BPA), phthalates, nitrosamines, lead, PVC, PET, and biologically harmful chemicals. Our stainless steel sippy cup has become one of our most popular items. Most of the sippy cups on the market have hard plastic spouts or rubber spouts. We 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 Cup, the little one is already used to the feeling of silicone so making the transition is quite simple. The base of the bottle is made of medical grade (18/8) stainless steel and has markings on the inside and outside to indicate volume.