Lifefactory baby bottles are made of the highest quality, thermal shock resistant borosilicate glass. This allows their bottles to transition safely from freezer to boiling water. The silicone sleeves provide a good gripping surface for little hands and help protect against the occasional drop. Compatible with most major breast pumps. BPA-free and phthalate-free. Includes polypropylene (PP#5) cap, ring and stopper and silicone nipple. Size: 4oz.