As baby grows the Lifefactory 9 oz borosilicate glass baby bottle is the next step up. The 9 oz. bottle comes with a silicone sleeve, polypropylene cap, ring, stopper, and a Stage 2 (3-6 months) silicone nipple. You'll appreciate the grippy surface of the colorful silicone sleeve, and you'll love the fact that you're using a glass bottle that is manufactured with high quality materials.