The box's inner dimensions measure 21-1/2" (L) x 7-3/8" (W) x 11-3/16" (H). Includes (2) straps and (4) strap clamps with screws. The Double Battery Box meets U.S. Coast Guard CFR 183.420 and ABYC E-10.7 specifications when used with (2) 6V Group GC2 batteries.