Dr. Brown's Natural Flow Anti-Colic Options+ Narrow Glass Baby Bottles – Size 1 Nipple Classic Dr. Brown's narrow glass baby bottles featuring the Natural Flow Anti-Colic Options+ vent system. Made from durable glass and designed to provide a consistent feeding experience. Details: * Brand: Dr. Brown's * Natural Flow Anti-Colic Options+ * Narrow glass bottle * Includes Size 1 nipple * Anti-colic vent system * Glass construction * Pre-owned condition set of 4