400 Amp Ultra Safe Lithium Jump Starter The GB20 is a portable lithium-ion battery jump starter pack that delivers 400-amps (4, 650 J3S) for jump starting a dead battery in seconds. It features a patented safety technology that provides spark-proof connections & reverse polarity protection making safe & easy for anyone to use. It's a powerful battery booster that doubles as a portable power source for recharging USB (Universal Serial Bus) devices, like a smartphone, tablet & more. Designed for a car, boat, motorcycle, RV & more with gas engines up to 4 liters. A lithium battery jump starter rated at 400 Amps (4, 650 Joules 3S). Spark-proof connections & reverse polarity protection. Recharges USB (Universal Serial Bus) devices, like smartphones, tablets, & more. 100 lumen LED flashlight with multiple modes, including SOS. Jump starts gas engines up to 4 liters. Provides up to 20 jump starts on a single charge.