Anti-Colic Base Vent Design: Innovative patented base vent separates air from liquid, ensuring smooth milk flow without air intake, reducing colic, reflux, and gas. Innovative Perforated Nipple Technology: The breast-like silicone nipple mimics the natural rhythm of breastfeeding, making mixed feeding effortless. Releases milk only when the baby actively drinks, allowing self-regulated flow and preventing choking. Sealed Design, No Milk Leakage: No air valve at the bottle neck, preventing milk from leaking. 4 Stage Nipple Flow: 4 flow options tailored to different age stages, preventing choking and supporting baby's development. BPA and BPS free. Easy to Clean:Freezer and dishwasher safe with only 4 pieces, easy to clean and assemble. Sterilized in bottle warmer, microwave, sterilizer and boiling water. Always Updating for Better Performance：As an innovative brand, we're not perfect but always working to improve. We appreciate your suggestion and keep updating our products for better experiences. Feel free to contact us with any issues - we're here to help you ASAP. Also, we offer a 90-day free return service. Anti-Colic Base Vent Design: Innovative patented base vent separates air from liquid, ensuring smooth milk flow without air intake, reducing colic, reflux, and gas.