Sea-Dog Line - Battery Box Strap - 54" - 4150941. Battery Box Strap & Brackets includes a woven polypropylene strap, injection molded nylon buckle, two brackets, and four #8 FH fasteners.. WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.