20mm Dia Black Phenolic Cap W/Polyethylene Cone Liner | Quantity: 40 - Discourage leakage, evaporation, and contamination using these polycone lined caps. These caps are made of sturdy plastic and feature a ribbed exterior, threaded interior, and internal polycone liner. Textured plastic caps are ideal for storing liquids, soaps, detergents, and bleaches.Plain Black Plastic Caps with Lining are offered in a variety of sizes and coordinate with Boston Round Glass Bottles.