"Pura Kiki 9oz/260ml Stainless Steel Insulated Infant Feeding Bottle VACUUM INSULATED: Keeps liquids warm for 6 hours or cold for up to 24 hours (iced) SAFE: only 100% plastic-free bottle on the market; only NonToxic Certified bottles on the planet Crafted from safe, anti-bacterial, #304 stainless steel and medical grade silicone BPA-free and will not leach toxins like plastic bottles and rings Internal volume markings make measuring your child's milk or other beverage a snap. Each ounce is marked and can be seen by glancing inside the bottle. Wide neck medium flow Pura Natural Vent Nipple crafted from 100% medical grade silicone Medical grade silicone bottle sleeve Medical grade silicone nipple cover Hand wash recommended.GENERAL INSTRUCTIONS: Wash before first use. Boil for 5 minutes to sterilize. Remove the sleeve from the bottle at least one time per week to clean between the bottle and sleeve, more often in humid climates. Dishwasher safe. How to install sleeve: Add baking soda to the inside of a dry sleeve then slide onto the bottle. Rinse thoroughly. OR At the sink, spread a pea-sized drop of liquid dish soap inside the sleeve then slide the sleeve onto the bottle. Rinse thoroughly."