Heavy Duty Large Battery Boxes are designed for large diesel or commercial applications. Made of rotationally molded premium grade hi-density polyethylene. Rugged and maintain tough impact properties down to -40 degrees F. Features seamless heavy wall construction, superior chemical resistance that eliminates electrolyte spills or grease contact and full flow ventilation that helps assure adequate cooling while enchancing battery life. Black Comply with USCG code of federal regulations 33, sub-chapter 183.420 when properly installed. Type 8D Double High