Product Description: The natural polypro analytical funnels are available in 4 sizes and are made of durable polypropylene plastic, which has good chemical resistance and provides an excellent moisture barrier. The plastic funnels feature internal ribs which promote rapid filtration and external ribs which aid in preventing air lock. These funnels are autoclavable, and feature long, narrow bores which are ideal for use with liquids. The polypro analytical funnels are also available in two combo kits, one featuring 6 small polypro funnels, and the other including 5 of our larger sized funnels.