evenflo Classic bottles and nipples provide a complete line of feeding solutions for your baby's changing needs. The Classic Nipples are made from soft silicone and feature Micro Air Vents. These special vents are designed to prevent nipple collapse, and promote a more comfortable feeding experience for baby. Designed for easy assembly and leak- free feeding these nipples are compatible with all Evenflo standard neck bottles. Rest assured, Evenflo baby bottle nipples are 100% free of BPA, polycarbonates, PVC and phthalates, and are also made of FDA approved food grade material.