Battery Boxes and Trays Durable polypropylene construction to ensure that all components are impervious to battery acid - All battery boxes and trays meet ABYC E-10 and U.S. Coast Guard #183.420 requirements. Battery Boxes include durable woven polypropylene hold down strap, polypropylene footman clamps, and stainless steel screws to complete installation. Larger cable outlet design prevents cable kinking to avoid potential loss of power. Extra-wide handles for easy transport, battery Trays include, adjustable crossbar adapts to a variety of battery sizes. Support rods feed upward and secure to crossbar with polypropylene retaining fasteners.