Second observation: it stands closed with a very beefy Velcro, along the pocket of his fourth installment in which leads the USB socket allows you to charge your devices. It is obviously essential to adequately protect them.
As for its effectiveness when deployed, it must be seen to realize that the announcement is not overdone (I admit I was very skeptical at first). I just test it for two days of feeble sun (in Belgium, late February) painfully succeeding an almost continuous barrage of two weeks. If you like painting, think about Van Gogh in the Borinage to that of Provence ... And it's true: despite these deplorable conditions, I get excellent electrical flow after three hours and easily recharges two phones that I had for my tests, and a camera. For a great summer, it must obviously work even better.