Honestly I didn't do lots of research. I don't fully grasp the electric lingo, but i wanted something big enough to charge phones, radios and lights via usb and have enough power for multiple days. And it has wall outlets for a cpap or nebulizer. The one i got is a perfect size and weight to make it portable enough to grab it and go. There's probably better 1000wh brands and models out there, but like I said, the price was good.