CAT CBC4W 4 Amp Waterproof Battery Charger/Maintainer 4 amp high frequency charger/maintainer; keeps battery at optimal capacity during off-season Waterproof - sealed from oil, dust and moisture to prevent corrosion 3 ways to connect - clamps, O-rings and 12V DC cord Fully-automatic, regulated charge for maximum efficiency ETL Listed for safety; submersible to 1 meter