Solar cells deliver up to a 24% conversion rate.Smart charging technology recognizes the input needed for a connected device and distributes current output accordingly,delivering up to 3.0A and cutting down on total charging time.Built-in loops and with carabiner easily attach to your backpack,tent or trees,and has a convenient pocket for the device being charged.You can keep all your devices fully charged. Spacious main compartment and numerous pouches.Special main pocket closing drawstring design, tight closure to prevent the items falling from the backpack.Shoes separated storing pouch, preventing the items inside backpack to be dirty.Two side pockets to carry more water bottles or umbrellas, And it meets size requirements for most airlines enough room for 3 or 4 days.