The Battery Tender Junior incorporates highly efficient surface mount technology electronic components. The interior is completely encapsulated, protected from shock, vibration, and moisture by an electrically insulating, thermally conductive, flame retardant, synthetic epoxy resin compound. It's tough, affordable, and a strong, innovative battery charging solution. This charger is no larger than a standard computer mouse yet packs 800 milliamps of pure constant current charging power. Coupled with a brain (IC chip), the charger will constantly monitor, charge, and then maintain your battery - even while totally submersed under water! Perfect for all outdoor types of ATVs, watercraft, motorcycles, boats, or anywhere water is a threat. Charges 12V @ 800mA.