The unique bottle design allows for easy heating and cooling of liquids. The lid is a 2oz, durable stainless steel design providing a built in measuring cup. It's dishwasher safe (top rack), although hand washing will extend the life of the designs. Winner of a Disney iParenting Media and a Mom's Best award! The bottle is compatible with most narrow necked nipples including the following: Evenflo Silicone Classic, Green to Grow Silicone, Momo Baby, Gerber Rubber Model 76226, Nuk Gerber Silicone, Nubby Non-Drip Nipples. 

GreeneSense: This product is made of stainless steel because of its antibacterial properties, high resistance to corrosion. It does not contain BPA, PVC and/or phthalates.