Black Screw Cap 20-400. This Fine Ribbed Polypropylene Screw-On Cap has an F-217 Foam Liner. This cap creates an airtight seal when securely screwed onto the bottle. Polypropylene offers high heat tolerance and fatigue resistance. The cap is designed to fit most any container with a 20/400 neck. It ensures a secure and reliable seal, enhancing efficiency by making it suitable for industries where freshness and containment are critical. Most suitable for industrial, food, pharmaceuticals, chemicals, fragrance and essential oils.