not to buy !!!! nice product but ineffective. ....

Apart from the practical fastening system, the solar panel not charge anything. Used in mountains late April by beautiful weather and sea at sea on a fine, after more than an hour in sunlight vacuum, (as recommended), the solar panel does not load when it is more perpendicular to the sun. Therefore impossible to hike or ski with a ski always oriented panel. At sea, although at platsur the top of the boat with 4 red LED indicating optimum exposure, recent motorola 30% load reached 28% in 30 minutes in flight mode and without GPS. The panel is equipped with a backup battery that should not keep his role and I do not understand is how it can easily charge a laptop. Poor design, he must miss a diode somewhere.
So not to buy, and well informed if solar panel and panel photo voltaic or sensible image is the same.