J series portable power source provide ultimate portable power It contains maintenance free battery delivers high peak amps and crank assist power Side wings protect cable and clamp in good storage and clean outlook Polarity connect reverse protection is available as well Perfect jump starter for professional and emergency rescue Feature: Low self discharge rate sealed battery Heavy-duty and flexible cable stay flexibility in cold weather and easy for storage Big copper jaw, 400A, metal clamps for solid connection to battery posts Battery level self test capability Easy to read battery status LEDs tell user percentage of battery charged Attached charger will cut off power when integrated battery charged automatically 12V DC outlet equips with overload and short circuit protection for external 12V accessory Reverse hookup connection guard battery, computer, and electronic/electric components (some units) Durable, corrosion-resistant polyethylene case, and side wings provide good storage space for cable and clamps Dead start function offer ultimate power direct from battery which enhance cranking amps to utmost (some units)