As baby grows the Lifefactory 4oz will be left in the past and the 9 oz borosilicate glass baby bottle is the next step up. With a variety of nipple sizes and sippy caps our bottle adapts to your baby's changing needs. The 9 oz. bottle comes with a silicone sleeve, polypropylene cap, ring, stopper, silicone nipple. With the grippy surface of the colorful silicone sleeve, these bottles are easy to grip and easy to love.