Narrow-Mouth Bottle high-density polyethylene, polypropylene screw closure. Popular, all-purpose Boston round bottles that are highly reliable and durable for long-term use. Ideal for storing, shipping and packaging liquids. Rigid and translucent, with excellent chemical resistance. Can be used with most corrosives. Notes (1) 500 mL size with longer neck and 50% wider mouth for easier filling and pouring. (2) 500 mL and 1000 mL sizes have 38-430 (38-mm) closures, and fit Eppendorf and Oxford reagent dispensers. (3) B6420-16B has buttress type cap.