I've never used it, but since they don't tell you the wire size, they can claim any charging current, since almost no one is even capable of measuring charging current. (My Note 3, when supplied with 5.2 volts (at the microUSB connector) with over 10 Amps available, still charges at only 1,200 mA. The phone just won't draw more current than that no matter how much the charger can put out and how thick the cable is.'
It's entirely possible to have a flat cable with 16 gauge wire - it will drop only 8mV per foot, which means that a 5.2 Volt charger with a 2 foot cable will still be delivering over 5 volts to the connector. It's also possible that they're using 24 guage wire, which drops 10 times that much, but it's nice and thin. So a 5 volt charger and 2 feet of #24 will give you about 4.92 Volts at the connector and it'll take longer to charge the battery.
If there's a spec on a product that determines whether the product will perform properly, and the company doesn't provide that spec, I'm immediately suspicious. Any wire will carry 2 Amps, so they're not saying anything with that claim. It's how much voltage that length of that size wire will drop at that current that matters, and that's determined by the resistance of the wire (which you can use a lot of online calculators to find if you have the wire gauge). (Well, sort of - 100 feet of #24 will drop over 5 volts at 1 Amp, so you have to feed it with more than 5 Volts to get it to be carrying 1 Amp. And a lot more if you want it to have 5 Volts at the end away from the charger.)
