The battery box's feature: Polypropylene co-polymer resistant to acid, gasoline, oil and solvents . The battery box special for using in RV caravan car or power supply needed with the feature :1, Polypropylene co-polymer resistant to acid, gasoline, oil and solvents 2, Optional external power off kit available3, Suitable for digital products and camping products4, DC 12V supply 5, Energy level ...