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. 3 packs of 4