Our wide neck borosilicate glass baby bottle is designed to grow alongside your little one. With a variety of nipple sizes and sippy caps our bottle adapts to baby's changing needs. The 8 oz. bottle comes with a silicone sleeve, polypropylene cap, ring, stopper, and a Stage 2 (3-6 months) silicone nipple that enhances feeding by providing a more natural experience. The wide neck makes it easy to fill and clean while the silicone sleeve makes it easy to grip. The following silicone nipple stages are available: Wide Neck Silicone Nipple Stage 2 (3-6 months) Wide Neck Silicone Nipple Stage 3 (6+ months)