Take the amperage ratings with a grain of sand. As with most of these Chinese products, the claims are often massively exaggerated.
For evidence, look at the wires to the clamps. They don't specify, but from photos they look to be maybe 8ga at most. Not terribly thick. If something actually pulled 1300A through those they're become a lightbulb filament in a split second.
There's a few Youtubers that have tested these, and quite often found the circuitry cuts off at small fractions at the rated load. When the safety feature is deliberately disabled, they only provide a burst of a couple hundred amps before the battery turns into a balloon and is instantly destroyed.
Not saying these don't work- I've used them and they can be helpful for a quick boost, but basing your choice just on more=better is not the way you want to go. Otherwise you'll end up with 3,000,000 maH cell phone batteries and 100,000 lumen headlights if advertising claims are to be believed.