The GB20 is a portable lithium-ion battery jump starter pack that delivers 500 amps for jump-starting a dead battery in seconds. It features a patented safety technology that provides spark-proof connections and reverse polarity protection making it safe and easy for anyone to use. It's a powerful battery booster that doubles as a portable power source for recharging USB devices like smartphones, tablets, and more. Designed for a car, boat, motorcycle, RV, and more with gas engines up to 4 liters.