This is a final sale item. No exchanges or returns ZoLi bottles are made from polypropylene plastic which is free of harmful chemicals such as Bisphenol-A (BPA). Thse bottles feature an integrated valve on the nipple that reduces air intake and nipple collapse. The unique valve works provides anti-colic relief without the extra parts to wash and assemble. BPA & Phthalate free Nitrosamine-free silicone nipple Patented integrated venting system to reduce colic Comes in 2-pack