This 48-400 black smooth top & side cap is made of polypropylene. These caps pair nicely with our 48mm plastic jars. Commonly used for food items, lotion, soaps, creams, and personal care items. Continuous thread caps are popular in a wide range of wholesale industries from food, personal care, pet care, household products, industrial products, health and beauty, arts, crafts, hobbies and just about any other market segment. This polypropylene (PP) cap has a high tolerance for heat and is very durable.