The new QuickBox™ Dual 27, 31 Battery Box is made of impact resistant, durable plastic that will not rust or corrode in the presence of acid, gasoline, oil, salt, water, or chemicals. Engineered and manufactured in the U.S.A by Quick Cable, you can be sure the Dual 27, 31 is built with the highest quality materials and components. Cover held firmly with convenient thumb screws, no special tools required. Cover can be locked for protection and tamper resistance. Vent holes in cover allow gases to escape, preventing dangerous hydrogen build up. Accommodates a variety of mounting options.