4 M +. Silicone. Sure flow vents for more liquid, less air in baby's tummy. Contains: 9 oz. Bottle with medium flow nipple, collar and cap. The Gerber Comfort Hold Bottle is specifically designed for both mom and baby. Cap protects nipple and prevents leaks. Comfort Latch Nipple has a natural shape for easier latch-on. Sure Flow Vents for more liquid, less air in baby's tummy. Soft grip collar designed for easy opening and closing. Wide design is easy to clean and fill. Unique triangular shape is comfortable to hold. Bottle fits directly into manual breast pump. Shatterproof bottle is sterilizer and dishwasher-safe. Comfort Feeding System is a line of products with interchangeable parts that expands your feeding options as a baby grows. Nipples made in Thailand to Gerber specifications.