Scribner Plastics 2000DB Utility Jug (5-gallonDark Blue) Manufactured from tough LLDPE polyethylene using our rotational molding process makes them the toughest around Extra heavy duty top features our unique, polyethylene gasket, with a larger and wider gasket seat and, unlike o - rings, there is no swelling and falling out after a month of use. Mate naturally and fit flush against walls and other flat surfaces New CNC machined thread design Square design eliminating unusable spaces around the jug