Dr. Brown's 120 ml Narrow Glass Bottle Sleeve in Mint, made from 100% Silicone. These sleeves protect Dr. Brown’s glass bottles against breakage during use, sterilization, or while in the dishwasher. They slide on quickly by wetting the inside of the sleeve and outside of the bottle. The see-through back panel allows you to view measurements and feed your baby without removing the sleeve. The sleeve can be removed for cleaning and sterilization, but doesn't need to be. The fitted silicone sleeve is grippy, making it easy to hold eco-friendly glass baby bottles and keep them safe. The soft, flexible silicone sleeves are durable, withstanding stretching and distorting from use.