BFXenon Jumper21000 Black Premium Portable Jump Starter/Power Bank (21000 mAh) Ultra Portable and light weight: Easily fits in a glove box, purse, pocket or book bag and only weighs about the same as 2 of the new iPad Airs making it easy to carry to work or class for use to recharge your phone and tablet Exclusive Safety Technology: Safety features such as surge, overload charging, reverse polarity and short circuit keep your battery from overheating that may result in unsafe conditions Rapid Recharging: You can use the portable jump starter and power bank to charge your electronics at an accelerated rate compared to other portable power supplies Jump Start your car as many as 20 times on a single charge. Only about 20 percent battery capacity is needed to jump start most cars. 21,000 mAh (750A peak) capacity recommended for cars up to 8.0 L gas and diesel engines Lifetime warranty: We back our craftsmanship with a 100 percent satisfaction guarantee and life time warranty. See website for specific details