The Lifefactory 4-Ounce Glass Baby Bottle is designed for infants aged 0-3 months. Made from high-quality thermal shock-resistant borosilicate glass, this bottle can safely transition from the freezer to boiling water. It features a protective silicone sleeve that not only helps prevent breakage but also provides a better grip for little hands. The bottle includes a Stage 1 silicone nipple, polypropylene cap, ring, and stopper, making it a complete feeding solution. Additionally, it is dishwasher safe, ensuring easy cleaning and maintenance.