The Natural Flow Bottle will be the last baby bottle you need; so make it your first. Created by a physician, Dr. Brown`s Natural Flow Baby Bottles are the only baby bottles with a patented internal vent system that actually helps to promote good hea lth in babies. By eliminating the vacuum and air bubbles, it helps to reduce feeding problems like colic, spit-up, burping and gas. And the positive pressure created by Dr. Brown`s system is as close to breastfeeding as your baby can get. This 8 oz. standard bottle features the two-piece patented internal vent, a level-one silicone feeding nipple, cleaning brush and instruction sheet. Choose from an array of feeding nipples to create your own personalized collection. Features:: -Standard 8 oz. - Ideal for newborns -Features internal vent -Includes level-one silicone feeding nipple -Cleaning brush -Instruction sheet -Choose from preemie, level-one, two, three, four, and y-cut feeding nipples -Preemie feeding nipples are ideal for pre-mature b abies -Level-one feeding nipples are ideal for newborns, level-two feeding nipples are ideal for 3 months and up, level-three feeding nipples are ideal for 6 months and up and level-four and y-cut feeding nipples are ideal for heavy liquids -Optional Microwave Steam Sterilizer is top rack dishwasher safe, fits four bottles and components at a time and includes one 4 oz. bottle, one 8 oz. bottle and tongs -Optional Insulated Bottle Tote Bag keeps bottles cold or warm and fits three standard or th ree wide-neck bottles; it features a moisture-resistant interior, zippered pockets, Velcro straps for stroller attachment, an adjustable carrying strap, a freezable gel pack and is easy-to-clean -Optional Bottle Drying Rack holds twelve standard or e ight wide-neck bottles, has two trays and drainage options, is easy-to-assemble, easy-to-clean and dishwasher safe -Awarded the American Baby Best of the Year Award in 2003, 2004 and 2006 Natural Flow Internal Vent System Diagra