Our baby bottles are made of the highest quality, thermal shock resistant borosilicate glass. This allows our 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. – Protective medical-grade silicone sleeve provides a tactile non-slip gripping surface and helps prevent breakage – While very durable, our bottles are still glass and are not unbreakable – Dishwasher safe (place cap parts and nipple on top rack/no need to remove silicone sleeve unless desired) – As baby grows we offer a range of caps (sippy and flat) to extend the life of your bottle – Includes polypropylene (PP#5) cap, ring and stopper and silicone nipple – Compatible with most major breast pumps – All components are made in the U.S. or Europe – Product assembled in the U.S. – All materials are FDA approved – BPA-free and phthalate-free – 9 oz (250 ml) with Stage 2 (3-6 mos) nipple