Lightweight, heavy duty corrosion-resistant polypropylene boxes are designed to secure and protect your battery. Both sizes include lift-off lid, durable woven hold-down strap, foot clamps and stainless steel screws. Choose small for group size 24 batteries or large for group sizes 27, 30 and 31. Both boxes meet USCG CFR 183.420 and ABYC E-010.7 specifications. Inside dimensions with lid (l x w x h) Small: 11.33" x 7.84" x 9.9"; Large: 13.87" x 7.87" x 10.9". Patent pending.