Size:Level 4 Replacement silicone nipple 3-packs for Dr. Brown's Natural Flow® baby bottles. Preemie flow for premature babies. All of our nipples are super-soft, made of high-grade silicone in Germany.3-Pack of Preemie Flow Nipples

• Exclusively for Dr. Brown's Natural Flow baby bottles.
• Made of super-soft, high-grade silicone.
• Each nipple level provides a different flow rate.
• All of these bottle nipples vary in size and shape.
• Find the bottle nipple that’s the perfect fit for your baby’s feeding needs.