Description Free of BPA, phthalates, nitrosamines, lead, PVC, PET, and biologically harmful chemicals. No-spill nipple which features our cross-cut design. The design mimics natural breastfeeding as it requires your little one to nurse to receive fluid. Anti-colic nipple helps reduce the incidence of gas and spit up. Unique one-piece design eliminates cleaning headaches and tricky assembly. No extra parts to lose. Extra soft, medical grade silicone spout-- provides an easier transition from breastfeeding to bottle feeding. Features side measurement markings. Light weight (nearly identical to our regular Thinkbaby bottle) Comes with Stage A nipple (for 0-6 months). Also available: Stage B nipple (for 6+ months) The transformational line: The Thinkbaby system allows parents to transform baby bottles into our award-winning Sippy Cup through the purchase of the Conversion Kit. The system saves parents' money and the environment from discarding baby bottles when it's time for the next stage in feeding. Comes with Travel Top, which reduces the chance of spillage during travel and protects the nipple from coming into contact with foreign substances. Does not leach chemicals to adversely affect the environment. No animal testing (Leaping Bunny member). Ingredients The bottle is made from 304 (18/8) medical grade stainless steel, the collar from polypropylene (no. 5 plastic), and the nipple from medical grade silicone. All of our testing is either chemical testing or biological testing (on cells). We utilize third-party globally certified laboratories to conduct our testing. Use & Care How do I care for my Thinkbaby bottle? Thinkbaby bottles are dishwasher safe (top rack recommended). When washing the baby bottles in the dishwasher, we recommend using a detergent that is free of chlorine. Most of the natural detergents on the market, from Eco Lever to Seventh Generation, should be free of toxic chemicals. If hand-washing, the American Pediatrics Association suggests using warm soapy water, but only if you live in an area with treated water systems. Before first use, we recommend sterilizing the bottles in boiling water for 2 to 5 minutes. We do not recommend utilizing sterilizers, as we cannot guarantee that the ones on the market were made with safe materials. The Thinkbaby of Steel is NOT microwave-safe. To prepare the nipple for first use, squeeze the top of the nipple and the venting tube. You will want to make sure they both open properly. When tightening down the collar of the bottle, do not over tighten, as this will reduce the amount of airflow into the baby bottle. What nipple flow should I use? The flow rates are determined by averages. Depending on your little one, you may need to adjust the flow rate that you purchase. The chart below should provide help in determining which to purchase. 0 to 6 months: Stage A Nipples 6 to 12 months: Stage B Nipples 9 to 36 months: Sippy Cup Spouts 18 to 48 months: Thinkster Straw Top Baby bottle nipples and spouts made from silicone will typically last 2 to 3 months prior to needing replacement. If you notice tears or breakage, discontinue use and replace. How does the venting system work? The venting systems work by allowing air to travel back into the baby bottle. Movement of air back into the baby bottle allows the bottle's internal pressure to reach equilibrium. This reduces the amount of suction required to get fluid out of the baby bottle. Research shows that having a venting system reduces the incidence of gas and spit up, as children take in less air when drinking when venting systems are present. The advantage to Thinkbaby's system is that it is built right into the baby bottle nipple. So, there are no extra parts to deal with and it's easy to clean. How do I convert the Thinkbaby bottle into the Sippy Cup or Straw Bottle? Remove the baby bottle nipple and replace with the Sippy Cup spout. Place the Sippy Cup handles around the top of the baby bottle and push down over the neck of the bottle. Tighten the collar with spout around the neck of the bottle and presto-chango! You have our award-winning Sippy Cup! Converting The Sippy Cup into The Thinkster: Take the collar off of the baby bottle (along with spout) and screw on the Thinkster top. Ta-da! The Thinkster! The Why Since 2006, Thinkbaby & Thinksport has been creating safe, highly functional, and sustainable products. We continue the safer products mission by targeting harmful consumer product categories and developing safer alternatives for a wide audience ranging from babies to athletes. With a team of physicians & scientists, Thinkbaby & Thinksport lead in the usage of safe materials for consumer products. As such, the company has a long list of FIRSTS 1st BPA free baby bottle line, 1st BPA free insulated sports bottle, 1st line of yoga mats free of harmful chemicals, and the 1st sunscreen to pass Whole Foods Premium Care requirements.