All Thinkbaby products are free of - bisphenol-a (BPA), phthalates, nitrosamines, lead, PVC, PET and biologically harmful chemicals. Our sippy cup easily become the Thinkster with the conversion kit. Simply unscrew the collar of the sippy cup and place the Thinkster top on the existing bottle. The no spill straw on the Thinkster features our cross cut design and eliminates spills. The extra soft, medical grade silicone straws provides easier transition from sippy cup to straw bottle. The award-winning Thinkbaby Thinkster comes with easy-to-close swivel top protecting the straw from coming into contact with foreign substances. Perfect for 16 to 48 months of age. Easy to clean and dishwasher safe. Bottles made from polypropylene and straws from extra, soft medical grade silicone.